Cleaner Production Assessment
in Meat Processing
COWI Consulting Engineers and Planners AS, Denmark
United Nations Environment Programme
Division of Technology, Industry and Economics
What is Cleaner Production? Why invest in Cleaner Production? Cleaner Production can be practised now Cleaner Production and sustainable development Cleaner Production and quality and safety Cleaner Production and environmental management systems OVERVIEW OF MEAT PROCESSING
Environmental impacts Environmental indicators CLEANER PRODUCTION OPPORTUNITIES
Livestock reception Stunning and bleeding Hide treatment of pigs Hide removal and dressing of cattle Evisceration and splitting Casings processing Paunch washing (cattle) Ancillary operations CLEANER PRODUCTION CASE STUDY
Phase I: Planning and organisation Phase II: Pre-assessment Phase III: Assessment Phase IV: Evaluation and feasibility study Phase V: Implementation and continuation CLEANER PRODUCTION ASSESSMENT
Planning and organisation Evaluation and feasibility study Implementation and continuation ANNEX 1 REFERENCES AND BIBLIOGRAPHY
Cleaner Production Assessment in Meat Processing
The purpose of the Industrial Sector Guides for Cleaner Production
Assessment is to raise awareness of the environmental impacts associated
with industrial and manufacturing processes, and to highlight the
approaches that industry and government can take to avoid or minimise
these impacts by adopting a Cleaner Production approach.
This guide is designed for two principal audiences:
• People responsible for environmental issues at meat processing plants (environmental managers or technicians) who seek information on howto improve production processes and products. In many countries,managers are ultimately responsible for any environmental harm causedby their organisation's activities, irrespective of whether it is causedintentionally or unintentionally.
• Environmental consultants, Cleaner Production practitioners, employees of industry bodies, government officers or private consultants thatprovide advice to the meat processing industry on environmental issues.
This guide describes Cleaner Production opportunities for improvingresource efficiency and preventing the release of contaminants to air, waterand land. The Cleaner Production opportunities described in this guide willhelp improve production as well as environmental performance.
Chapter 1 provides a brief introduction to the concept of Cleaner Productionand the benefits that it can provide.
Chapter 2 provides an overview of the meat processing industry includingprocess descriptions, environmental impacts and key environmentalindicators for the industry.
Chapter 3 describes Cleaner Production opportunities for each of the unitoperations within the process and provides examples of their successfulapplication. The processes discussed in most detail are the slaughtering ofpigs and cattle, carcass dressing, casings and offal processing andrendering, as well as cleaning and ancillary operations. Quantitative data forthe inputs and outputs associated with each unit operation are provided asan indication of typical levels of resource consumption and wastegeneration.
Chapter 4 provides a case study demonstrating the application of CleanerProduction at a meat processing plant.
Chapter 5 describes the Cleaner Production assessment methodology indetail. It can be used as a reference guide for carrying out a CleanerProduction assessment within an organisation.
Annex 1 contains a reference and bibliography list.
Annex 2 contains a glossary and list of abbreviations.
Annex 3 contains a list of literature and contacts for obtaining furtherinformation about the environmental aspects of the industry.
Annex 4 contains background information about the UNEP Division ofTechnology, Industry and Economics (UNEP DTIE).
Monetary figures quoted in this guide are based on 1995–98 figures andare presented as US dollars for consistency. As prices vary from country tocountry and from year to year, these figures should be used with care.
They are provided as a guide to capital expenditure and savings only.
This guide has been published jointly by the UNEP Division of Technology,
Industry and Economics (UNEP DTIE) and the Danish Environmental
Protection Agency, and funded by the Danish Ministry of Foreign Affairs.
The following people produced the guide:
• Mr Poul-Ivar Hansen, Danish Meat Research Institute, Denmark; • Mr Kim Christiansen, Sophus Berendsen, Denmark; • Mr Bent Hummelmose, COWI, Denmark.
• Mr Erwin Van den Eede, Danish Environmental Protection Agency • Ms Mariane Hounum, Danish EPA; • Mr Søren Kristoffersen, Danish EPA; • Mr John Kryger, DTI/International; • Mr Sybren de Hoo, UNEP DTIE, now Rabo Bank, the Netherlands; • Mr Hugh Carr-Harris, BADO, now Enviros-RIS, United Kingdom.
Reviewers and editors: • Mr Bob Pagan, UNEP Working Group for Cleaner Production in the Food Industry, on behalf of Uniquest Pty Ltd., Australia; • Ms Marguerite Renouf, UNEP Working Group for Cleaner Production in the Food Industry, on behalf of Uniquest Pty Ltd., Australia; • Dr Lewis Atkinson, Meat & Livestock Australia Ltd., Australia; • Mr Surya Prakash Chandak, Cleaner Production Co-ordinator, Production and Consumption Unit, UNEP DTIE.
UNEP staff involved: • Mrs Jacqueline Aloisi de Larderel, Director, UNEP DTIE; • Mr Fritz Balkau, Chief, Production and Consumption Unit, UNEP DTIE; • Ms Kristina Elvebakken, UNEP DTIE; • Ms Wei Zhao, Programme Officer, Production and Consumption Unit, Cleaner Production Assessment in Meat Processing
This document is one in a series of Industrial Sector Guides published by
the United Nations Environment Programme UNEP Division of Technology,
Industry and Economics (UNEP DTIE) and the Danish Environmental
Protection Agency. The documents in this series include:
Cleaner Production Assessment in Dairy Processing; • Cleaner Production Assessment in Meat Processing; and • Cleaner Production Assessment in Fish Processing.
This document is a guide to the application of Cleaner Production to themeat processing industry, with a focus on the slaughtering of cattle andpigs at abattoirs. Its purpose is to raise awareness of the environmentalimpacts of meat processing, and to highlight approaches that industry andgovernment can take to avoid or minimise these impacts by adopting aCleaner Production approach.
The life cycle of meat products commences with the production oflivestock. Beef cattle are raised on grazing properties or in intensivefeedlots. Pigs are generally raised intensively at piggeries. At abattoirs,livestock are slaughtered and the carcasses dressed to produce sides ofmeat. The basic steps in this process are stunning and bleeding, hideremoval or hide treatment, evisceration and carcass dressing. It is commonfor abattoirs to also undertake the boning of carcasses to produce smallerretail cuts of meat.
Even though meat is the most significant product from the abattoir, by-products such as hides, blood, fat, bone and offal are also produced. Theprofitability of an abattoir can often depend on the extent to which thesematerials are utilised. Edible by-products are further processed into saleableproducts and inedible by-products are converted into animal feedsupplements by rendering.
From the abattoir, carcasses, boned meat and edible by-products aredistributed on a wholesale basis to butchers or to other meat processingplants for further processing into specialty products and processed meats.
Retail cuts of meat are packaged and then further distributed to retailoutlets. Fresh meat products are highly perishable and refrigerated storageis required throughout their life to maintain eating appeal and preventmicrobiological spoilage. The life cycle ends with consumption by theconsumer and disposal or recycling of the packaging.
In this guide, the upstream process of livestock production, and thedownstream processes of distribution and post-consumer packagingmanagement are not covered. The manufacture of specialty meat productsand processed meats is also not covered. The guide focuses on activities,which occur at abattoirs, namely, slaughter and its associated processes.
The slaughtering of livestock is a significant contributor to the overallenvironmental load produced over the life cycle of meat production andconsumption. Therefore, the application of Cleaner Production in this phaseof the life cycle is important.
As with many food processing industries, the key environmental issuesassociated with abattoir operations are the high consumption of water, thegeneration of high-strength effluent streams, the consumption of energyand the generation of by-products. For some sites, noise and odour mayalso be concerns.
This guide contains background information about the industry and its
environmental issues, including quantitative data on rates of resource
consumption and waste generation, where available. It also describes
examples of ways to improve the environmental performance of abattoir
operations through the application of Cleaner Production. Case studies of
successful Cleaner Production projects are also presented.
Cleaner Production
Cleaner Production is defined as the continuous application of an
integrated, preventive, environmental strategy applied to processes,
products, and services to increase overall efficiency and reduce risks to
humans and the environment
. It is different to the traditional ‘pollution
control' approach to environmental management. Where pollution control is
an after-the-event, ‘react and treat' approach, Cleaner Production is a
proactive, ‘anticipate and prevent' philosophy.
Cleaner Production has most commonly been applied to production
processes, by bringing about the conservation of resources, the elimination
of toxic raw materials, and the reduction of wastes and emissions.
However it can also be applied throughout the life cycle of a product, from
the initial design phase, through to the consumption and disposal phase.
Techniques for implementing Cleaner Production include improved
housekeeping practices, process optimisation, raw material substitution,
new technology or new product design.
The other important feature of Cleaner Production is that by preventing
inefficient use of resources and avoiding unnecessary generation of waste,
an organisation can benefit from reduced operating costs, reduced waste
treatment and disposal costs and reduced liability. Investing in Cleaner
Production, to prevent pollution and reduce resource consumption is more
cost effective than relying on increasingly expensive ‘end-of-pipe' solutions.
There have been many examples that demonstrate the financial benefits of
the Cleaner Production approach as well as the environmental benefits.
Water consumption
Water is used for the watering and washing of livestock, the washing of
trucks, washing of carcasses and by-products, and for cleaning and
sterilising equipment and process areas.
Rates of water consumption can vary considerably depending on the scale
of the plant, the age and type of processing, the level of automation, and
cleaning practices. Typical figures for fresh water consumption are
2–15 m3 per tonne of live carcass weight.
In most parts of the world, the cost of water is increasing as supplies of
fresh water become scarcer and as the true environmental costs of its
supply are taken into consideration. Water is therefore becoming an
increasingly valuable commodity and its efficient use is becoming more
Strategies for reducing water consumption can involve technological
solutions or equipment upgrade. However reviewing cleaning procedures
and operator practices can make some of the most significant gains.
Cleaner Production Assessment in Meat Processing
Some key strategies for reducing water consumption are listed below, andthe use of these techniques would represent best practice for the industry: • undertaking dry cleaning of trucks prior to washing with water; • using automatically operated scalding chambers rather than scalding tanks for the de-hairing of pigs; • using offal transport systems that avoid or minimise the use of water; • using dry dumping techniques for the processing of cattle paunches and pig stomachs that avoid or minimise the use of water, instead ofwet dumping techniques; • reusing relatively clean wastewaters from cooling systems, vacuum pumps etc. for washing livestock if possible; • reusing final rinse waters from paunch and casings washing for other non-critical cleaning steps in the casings department; • reusing wastewaters from the slaughter floor, carcass washing, viscera tables and hand-wash basins for the washing of inedibleproducts if possible; • reusing cooling water from the singeing process for other application in the pig de-hairing area; • reusing the final rinse from cleaning operations for the initial rinse on the following day; • using dry cleaning techniques to pre-clean process areas and floors before washing with water; • using high pressure rather than high volume for cleaning surfaces; • using automatic control systems to operate the flow of water in hand-wash stations and knife sterilisers.
Effluent discharge
Most water consumed at abattoirs ultimately becomes effluent. Abattoir
effluent contains high levels of organic matter due to the presence of
manure, blood and fat. It can also contain high levels of salt, phosphates
and nitrates. The most significant contributor to the organic load is blood,
followed by fat. Blood is also the major contributor to the nitrogen content
of the effluent stream. Salt and phosphorus originate from the presence of
manure and stomach contents in the effluent. At those plants where
rendering occurs, the effluent from rendering typically represents the single
most significant source of pollutant load in abattoir effluent.
It follows therefore that effluent quality depends on the extent to which
blood, fat, manure and stomach contents are excluded from the effluent
stream, and whether or not rendering occurs at the site. Typical values for
the organic loads discharged in abattoir effluent are 4–18 kg COD per
tonne of live carcass weight.
Strategies for reducing the pollutant load of abattoir effluent principally
focus on excluding blood, fat, manure and scraps of meat from the effluent
stream. This means capturing materials before they enter drains and using
dry cleaning methods.
Some key strategies are listed below: • maximising the segregation of blood by designing suitable blood collection facilities and allowing sufficient time for bleeding, typicallyseven minutes; • sweeping up solid materials for use as by-products, instead of washing them down the drain; • fitting drains with screens and/or traps to prevent solid materials from entering the effluent system; • using offal transport systems that avoid or minimise the use of water; • using water sprays with a pressure of less than 10 bar for carcass washing to avoid removing fat from the surface; • using dry cleaning techniques to pre-clean process areas and floors before washing with water; • segregating high-strength effluent streams, such as rendering effluent and wastewaters from paunch washing, and treating them separately.
Energy consumption
Approximately 80–85% of total energy consumed by abattoirs is provided
by thermal energy from the combustion of fuels in on-site boilers. Thermal
energy is used to heat water for cleaning, pig scalding, rendering, blood
coagulation and blood drying. The remaining 15–20% of energy is provided
by electricity, which is used for operating equipment in the slaughter and
boning areas, for by-product processing, and for refrigeration and
compressed air. Typical ranges for the energy consumption are
1200–4800 MJ per tonne of hot standard carcass weight.
Energy is an area where substantial savings can be made almost
immediately with no capital investment, through simple housekeeping
efforts. Additional savings can be made through the use of more energy-
efficient equipment and heat recovery systems. Some key strategies are
listed below:
• implementing switch-off programs and installing sensors to turn-off or power-down lights and equipment when not in use; • improving insulation on heating or cooling systems and pipework • insulating and covering scald tanks to prevent heat loss; • recovering waste heat from effluent streams, vents, exhausts and • recovering evaporative energy in the rendering process using multi- effect evaporators; • maintaining a leak-free compressed air system; • favouring more efficient equipment; • improving maintenance to maximise energy efficiency of equipment; • maintaining optimal combustion efficiencies on boilers; • eliminating steam leaks; In addition to reducing a plant's demand for energy, there are opportunitiesfor using more environmentally benign sources of energy. Opportunitiesinclude replacing fuel oil or coal with cleaner fuels, such as natural gas, Cleaner Production Assessment in Meat Processing
purchasing electricity produced from renewable sources, or co-generation
of electricity and heat on site. For some plants it may also be feasible to
recover methane from the anaerobic digestion of high-strength effluent
streams to supplement fuel supplies.
Implementing a Cleaner Production assessment
This guide contains information to help the reader undertake a Cleaner
Production assessment at an abattoir. A Cleaner Production assessment is a
systematic procedure for identifying areas of inefficient resource
consumption and poor waste management, and for developing Cleaner
Production options. The methodology described in this guide is based on
that developed by UNEP and UNIDO, and consists of the following basic
• planning and organising the Cleaner Production assessment; • pre-assessment (gathering qualitative information about the organisation and its activities); • assessment (gathering quantitative information about resource consumption and waste generation and generating Cleaner Productionopportunities); • evaluation and feasibility assessment of Cleaner Production • implementation of viable Cleaner Production opportunities and developing a plan for the continuation of Cleaner Production efforts.
It is hoped that by providing technical information on known CleanerProduction opportunities and a methodology for undertaking a CleanerProduction assessment, individuals and organisations within the meatprocessing industry will be able to take advantage of the benefits thatCleaner Production has to offer.
Chapter 1 Cleaner Production
1.1 What is Cleaner Production?
Over the years, industrialised nations have progressively taken different
approaches to dealing with environmental degradation and pollution
problems, by:
• ignoring the problem; • diluting or dispersing the pollution so that its effects are less harmful or apparent; • controlling pollution using ‘end-of-pipe' treatment; • preventing pollution and waste at the source through a ‘Cleaner The gradual progression from ‘ignore' through to ‘prevent' hasculminated in the realisation that it is possible to achieve economicsavings for industry as well as an improved environment for society.
This, essentially, is the goal of Cleaner Production.
Definition of Cleaner Cleaner Production is defined as the continuous application of an integrated preventive environmental strategy applied to processes,products and services to increase overall efficiency and reduce risks tohumans and the environment.
• For production processes, Cleaner Production involves the conservation of raw materials and energy, the elimination of toxicraw materials, and the reduction in the quantities and toxicity ofwastes and emissions.
• For product development and design, Cleaner Production involves the reduction of negative impacts throughout the life cycle of theproduct: from raw material extraction to ultimate disposal.
• For service industries, Cleaner Production involves the incorporation of environmental considerations into the design anddelivery of services.
The key difference between pollution control and Cleaner Production is Cleaner Production and one of timing. Pollution control is an after-the-event, ‘react and treat' pollution control approach, whereas Cleaner Production reflects a proactive, ‘anticipateand prevent' philosophy. Prevention is always better than cure.
This does not mean, however, that ‘end-of-pipe' technologies will neverbe required. By using a Cleaner Production philosophy to tackle pollutionand waste problems, the dependence on ‘end-of-pipe' solutions may bereduced or in some cases, eliminated altogether.
Cleaner Production can be and has already been applied to raw materialextraction, manufacturing, agriculture, fisheries, transportation, tourism,hospitals, energy generation and information systems.
It is important to stress that Cleaner Production is about attitudinal aswell as technological change. In many cases, the most significantCleaner Production benefits can be gained through lateral thinking, 1 This chapter has been adapted from a UNEP publication, Government Strategies and Policies for Cleaner Production, 1994.
Cleaner Production Assessment in Meat Processing
without adopting technological solutions. A change in attitude on thepart of company directors, managers and employees is crucial to gainingthe most from Cleaner Production.
Applying know-how Applying know-how means improving efficiency, adopting bettermanagement techniques, improving housekeeping practices, and refiningcompany policies and procedures. Typically, the application of technicalknow-how results in the optimisation of existing processes.
Technological improvements can occur in a number of ways: • changing manufacturing processes and technology; • changing the nature of process inputs (ingredients, energy sources, recycled water etc.); • changing the final product or developing alternative products; and • on-site reuse of wastes and by-products.
Types of Cleaner Production options
Improvements to work practices and propermaintenance can produce significant benefits. Theseoptions are typically low cost.
Optimising existing processes can reduce resource consumption. These options are typically low tomedium cost.
Environmental problems can be avoided by replacing hazardous materials with more environmentallybenign materials. These options may require changesto process equipment.
Adopting new technologies can reduce resource consumption and minimise waste generation throughimproved operating efficiencies. These options areoften highly capital intensive, but payback periodscan be quite short.
Changing product design can result in benefits throughout the life cycle of the product, includingreduced use of hazardous substances, reduced wastedisposal, reduced energy consumption and moreefficient production processes. New product design isa long-term strategy and may require new productionequipment and marketing efforts, but paybacks canultimately be very rewarding.
Chapter 1 Cleaner Production
1.2 Why invest in Cleaner Production?
Investing in Cleaner Production, to prevent pollution and reduce resource
consumption is more cost effective than continuing to rely on
increasingly expensive ‘end-of-pipe' solutions.
When Cleaner Production and pollution control options are carefully versus pollution control evaluated and compared, the Cleaner Production options are often morecost effective overall. The initial investment for Cleaner Productionoptions and for installing pollution control technologies may be similar,but the ongoing costs of pollution control will generally be greater thanfor Cleaner Production. Furthermore, the Cleaner Production option willgenerate savings through reduced costs for raw materials, energy, wastetreatment and regulatory compliance.
Greener products The environmental benefits of Cleaner Production can be translated intomarket opportunities for ‘greener' products. Companies that factorenvironmental considerations into the design stage of a product will bewell placed to benefit from the marketing advantages of any future eco-labelling schemes.
Some reasons to invest in Cleaner Production
• improvements to product and processes; • savings on raw materials and energy, thus reducing production • increased competitiveness through the use of new and improved • reduced concerns over environmental legislation; • reduced liability associated with the treatment, storage and disposal of hazardous wastes; • improved health, safety and morale of employees; • improved company image; and • reduced costs of end-of-pipe solutions.
1.3 Cleaner Production can be practiced now
It is often claimed that Cleaner Production techniques do not yet exist or
that, if they do, they are already patented and can be obtained only
through expensive licences. Neither statement is true, and this belief
wrongly associates Cleaner Production with ‘clean technology'.
Cleaner Production also Firstly, Cleaner Production depends only partly on new or alternative covers changing technologies. It can also be achieved through improved management attitudes and techniques, different work practices and many other ‘soft' approaches.
Cleaner Production is as much about attitudes, approaches andmanagement as it is about technology.
Secondly, Cleaner Production approaches are widely and readily techniques already exist available, and methodologies exist for its application. While it is true thatCleaner Production technologies do not yet exist for all industrialprocesses and products, it is estimated that 70% of all current wastesand emissions from industrial processes can be prevented at source bythe use of technically sound and economically profitable procedures(Baas et al., 1992).
Cleaner Production Assessment in Meat Processing
1.4 Cleaner Production and sustainable development
In the past, companies have often introduced processes without
considering their environmental impact. They have argued that a trade-
off is required between economic growth and the environment, and that
some level of pollution must be accepted if reasonable rates of economic
growth are to be achieved. This argument is no longer valid, and the
United Nations Conference on Environment and Development (UNCED),
held in Rio de Janeiro in June 1992, established new goals for the world
community that advocate environmentally sustainable development.
Economy and Cleaner Production can contribute to sustainable development, as environment go hand in endorsed by Agenda 21. Cleaner Production can reduce or eliminate the need to trade off environmental protection against economic growth,occupational safety against productivity, and consumer safety againstcompetition in international markets. Setting goals across a range ofsustainability issues leads to ‘win–win' situations that benefit everyone.
Cleaner Production is such a ‘win–win' strategy: it protects theenvironment, the consumer and the worker while also improvingindustrial efficiency, profitability and competitiveness.
Cleaner Production can Cleaner Production can be especially beneficial to developing countries provide advantages for and those undergoing economic transition. It provides industries in these all countries countries with an opportunity to ‘leapfrog' those more establishedindustries elsewhere that are saddled with costly pollution control.
1.5 Cleaner Production and quality and safety
Safety and quality are very important issues for the food industry. While
food safety has always been an important concern for the industry, it
has received even greater attention over the past decade due to larger
scales of production, more automated production processes and more
stringent consumer expectations. A stronger emphasis is also being
placed on quality due to the need for companies to be more efficient in
an increasingly competitive industry.
In relation to food safety, Hazard Analysis Critical Control Point (HACCP)
has become a widely use tool for managing food safety throughout the
world. It is an approach based on preventing microbiological, chemical
and physical hazards within food production processes by anticipating
and preventing problems, rather than relying on inspection of the
finished product.
Similarly, quality systems such as Total Quality Management (TQM) are
based on a systematic and holistic approach to production processes
and aim to improve product quality while lowering costs.
Cleaner Production should operate in partnership with quality and safety
systems and should never be allowed to compromise them. As well,
quality, safety and Cleaner Production systems can work synergistically
to identify areas for improvement in all three areas.
Chapter 1 Cleaner Production
1.6 Cleaner Production and environmental management
Environmental issues are complex, numerous and continually evolving,and an ad hoc approach to solving environmental problems is no longerappropriate. Companies are therefore adopting a more systematicapproach to environmental management, sometimes through aformalised environmental management system (EMS).
An EMS provides a company with a decision-making structure andaction programme to bring Cleaner Production into the company'sstrategy, management and day-to-day operations.
As EMSs have evolved, a need has arisen to standardise theirapplication. An evolving series of generic standards has been initiated bythe International Organization for Standardization (ISO), to providecompany management with the structure for managing environmentalimpacts. The UNEP/ICC/FIDIC Environmental Management SystemTraining Resource Kit, mentioned above, is compatible with theISO 14001 standard.
EMS training resources UNEP DTIE, together with the International Chamber of Commerce (ICC) and the International Federation of Engineers (FIDIC), has published anEnvironmental Management System Training Resource Kit, whichfunctions as a training manual to help industry adopt EMSs.
Chapter 2 Overview of Meat Processing
Meat and meat products are an important component of diet in many
parts of the world, particularly in developed nations, where the
consumption of animal protein per head of population is the highest. For
developing nations, the production and consumption of meat is
increasing as levels of affluence increase.
Table 2—1 provides an overview of world meat production, showing the
contributions of different meat species to overall meat-production and
the relative scales of production for the major meat producing countries.
Of the red meats, pork and beef are produced in the greatest quantities.
Poultry meat is also a major source of world meat production. China and
the United States of America are the world's largest producers of beef
and pork. Brazil, Mexico, the Russian Federation and a number of
western European countries are also large producers.
The slaughter of livestock to produce meat and meat products is a
widespread activity and can be an important industry in many countries.
Table 2—1 Overview of world meat production 1
Total world production Percentage of world Major producing countries Russian Federation United States of America 1 Derived from data presented in Ockerman and Hansen, 2000 Meat processing is the generic term used to describe the industry.
However a number of terms are used to describe the facilities at whichmeat processing occurs, including abattoirs, slaughterhouses and meatpacking plants.
Cleaner Production Assessment in Meat Processing
The terms abattoir and slaughterhouse are synonymous and refer toplants which slaughter livestock and dress carcasses only, often withlimited or no processing of by-products. The products from these plantsare usually dressed carcasses, which are sold on a wholesale basis tobutchers and other meat processing plants. However, it is common forabattoirs or slaughterhouses to also undertake the boning of carcassesto produce retail cuts.
Meat packing plants undertake slaughter and carcass dressing, but alsoundertake the further processing of meat products and by-products. Ameat packing plant will often undertake the cooking, curing, smokingand pickling of meat and the manufacture of sausage.
Focus of this guide Since livestock slaughter along with its associated activities contributesthe most to pollution loads from the meat processing industry as awhole, this guide focuses on abattoir (or slaughterhouse) operations.
There is no discussion on the further processing of meat. For simplicitythe term abattoir will be used throughout this document.
Slaughtering can take place either on farms, at butchers' premises or atabattoirs. Consequently, the scale on which slaughtering takes place canvary enormously, from slaughtering only a few animals through tothousands each day. Methods and equipment for slaughtering may vary,but the basic principles are independent of plant capacity.
Large, highly automated abattoirs may specialise in the slaughter of onespecies of livestock. However it is also common for abattoirs to kill anumber of species at a single premises. Species slaughtered include beefcattle, pigs, sheep, goats, horses and deer. This guide covers theslaughter of beef cattle and pigs only and does not discuss the otherspecies specifically. However, many of the Cleaner Production principleswill apply also to them.
For small-scale operations taking place on farms or at butchers'premises, mechanisation is limited and extensive use is made of all by-products, meaning that very little waste and pollution are created. Thisguide does not deal with such small-scale operations, since the CleanerProduction opportunities described in this guide are generally notapplicable or viable in these situations. Instead, the guide describes theapplication of Cleaner Production to medium and large-scale abattoirs.
An increasing trend in many countries is for abattoirs to incorporaterendering facilities to process solid by-product materials into meat mealand tallow. For abattoirs without rendering facilities, by-products aresent to independent rendering plants. German abattoirs, for example, donot undertake rendering since by law it must be performed in a separateoff-site facility.
Units of production There are a number of units used to describe the scale of production inabattoirs. Commonly used units are per head of livestock slaughtered,tonne of live carcass weight (LCW), tonne of dressed weight (DW) ortonne of hot standard carcass weight (HSCW). Units based on carcassweight are often most useful because they allow for comparisonbetween abattoirs slaughtering livestock with different unit weights.
Data presented in this document are reported according to the unitsused in the original source, therefore the units may vary.
Chapter 2 Overview of Meat Processing
2.1 Process overview
The generic processes that take place at abattoirs are stunning and
bleeding, hide removal or treatment, evisceration, carcass dressing and
washing. Many abattoirs also have a boning process in which finished
carcasses are cut into retail portions. Most abattoirs also have casings
and offal processing departments, which produce value-added products
from the casings (intestinal tract) and edible offal. The sections that
follow provide a brief description of these processes.
2.1.1 Slaughtering and processing of pigs
The basic process for slaughtering and processing pigs is shown in
Figure 2—1.
Pre-handling of pigs Pigs are delivered to the abattoir in trucks, and held for one to two daysin holding yards. They are generally fasted for a day to reduce theamount of intestinal contents.
Stunning and bleeding Pigs are stunned using an electric shock or by anaesthetising in carbondioxide, after which they are bled. Bleeding, also referred to as sticking,is carried out using a hollow knife, which directs the blood to acollection trough, from where it is pumped to an agitated tank for furtherprocessing.
Dehairing and finishing Before being processed further, hair is removed from the pig carcasses,by scalding in hot water followed by scraping. Carcasses are then singedto remove any remaining hair. This process leaves the hide almost whitein colour, clean and smooth without any trace of hair.
Evisceration and After dehairing and hide finishing, the carcasses pass to the evisceration area, where the stomachs are opened and the viscera removed. Thebreastbone is split and the plucks (heart, liver and lungs) are loosenedand removed. The carcasses are then de-headed and split along thebackbone. Finally, the carcasses are chilled rapidly overnight before thesubsequent processes of cutting and boning can take place.
Edible offal components and casings (intestinal tract) are separated fromthe viscera and sent on for cleaning and further processing, generally inother parts of the plant.
At various stages in the process, inedible by-products such as bone, fat,heads, hair and condemned offal are generated. These materials are sentto a rendering plant either on site or off site for rendering into feedmaterials and tallow.
Cleaner Production Assessment in Meat Processing
Livestock reception and truck washing Dehairing and hide Casings processing Cutting and boning Meat for consumption Figure 2—1 Flow diagram for slaughtering of pigs
Table 2—2 is a summary of the major products and by-products fromthe slaughter of a 90 kg pig, including an indication of the relativeproportions.
Table 2—2 Products and by-products from the slaughter of a 90 kg pig
Weight (kg)
Percentage of LCW
Live carcass weight (LCW)
Inedible material for rendering (bones, fat, head, hair, condemnedoffal etc.) Edible material (tongue, liver, heart, kidneys, trotters) Miscellaneous (stomach contents, shrinkage, blood loss etc.) A pig carcass can be utilised to a much greater extent than any otherfarm animal species (up to 70% utilisation. This is because pigs haveone stomach instead of four and are dressed with the feet and skin lefton instead of removed. In addition, the proportion of edible componentsis higher than for cattle.
Chapter 2 Overview of Meat Processing
2.1.2 Slaughtering and processing of cattle
The live weight of cattle slaughtered for meat production can vary from
250 kg to 600 kg, depending on the age and breed of the animal. As a
guide, heifers weigh 250–300 kg, cows 350–400 kg, and steers
400–600 kg.
The basic slaughtering procedure for beef cattle has become more
automated and efficient over the past few decades. Most improvements
have occurred in stunning, hide removal, evisceration and splitting
techniques. As an example, processing rates in the United States now
average around 350 head per hour (Savell and Smith, 1998).
The basic process for the slaughtering and processing of cattle is shown
in Figure 2—2.
Pre-handling of cattle Cattle are delivered to the abattoir in trucks and unloaded into holdingpens, where they are rested for one or two days before slaughter. Anycattle classed as ‘dirty' are washed.
Stunning and bleeding The cattle are led to the slaughter area where they are stunned using abolt pistol or electric shock. They are then shackled by a hind leg andhoisted onto an overhead rail or dressing trolley. Bleeding, or sticking,then takes place, with the blood collected in a trough for disposal or forfurther processing.
Dressing and hide The bled carcasses are conveyed to the slaughter hall where dressing and evisceration take place. The first stage of this process, dressing, canbe performed as the carcass hangs from the overhead rail, or the animalcan be unshackled and laid in a cradle. The head and hoofs are removed,the head is cleaned with water, and the tongue and brain are recovered.
Hides are then removed and conveyed to the hide processing area,where they are preserved by salting or chilled on ice.
The carcasses are then opened to remove the viscera. The stomach(paunch) and intestines are emptied of manure and cleaned inpreparation for further processing. Edible offal (tongue, lungs, heart andliver) is separated, washed and chilled. The carcasses are then split,rinsed and then conveyed to a cold storage area for rapid chilling.
Cutting and boning Carcass cutting and boning often take place after chilling, since acarcass is easier to handle and cut when it is chilled. Boning is the termused to describe the process of cutting meat away from the bone.
Recent developments in processing technology have made it possible toundertake boning while the carcass is still warm, eliminating the need tochill the carcass at this stage in the process. This is referred to as ‘hotboning'.
Carcasses and viscera are inspected to determine if they are suitable forhuman consumption. Each carcass and its components are identified andkept together wherever possible until inspection is complete.
At various stages in the process, inedible by-products such as bone, fat,heads, hair and condemned offal are generated. These materials are sentto a rendering plant either on site or off site for rendering into feedmaterials.
Table 2—3 is a summary of the major products and by-products fromthe slaughter of a 400 kg animal, including an indication of theproportions of each.
Cleaner Production Assessment in Meat Processing
Dressing (head, hoof and hide removal) Hide preservation Casings processing Cutting and boning Meat for consumption Figure 2—2 Flow diagram for slaughtering of cattle
Table 2—3 Products and by-products from the slaughter of 400 kg beef

Weight (kg)
Percentage of LCW
Live carcass weight (LCW)
Inedible material for rendering (bones, fat, head, condemned offaletc.) Edible offal (tongue, liver, heart, kidneys, plucks etc.) Miscellaneous (paunch manure, shrinkage, blood loss etc.) Chapter 2 Overview of Meat Processing
2.1.3 By-product processing
Meat is the most significant product from the abattoir, by weight and
also in monetary terms. However, by-products can contribute
significantly to the profitability of an abattoir operation since they
generally have a commercial value.
If animal by-products are not used effectively a valuable source of
revenue is lost, and the added and increasing cost of disposal of these
products is incurred by the company. Also, from an environmental
perspective, utilisation of by-products reduces the overall environmental
load of the process.
The modern livestock industry is an effective user of by-products.
However more than 2% of the carcass weight is often unaccounted for
and is usually lost to effluent. Therefore, there is potentially more that
can be done.
By-products from livestock slaughter include, but are not limited to
(Ockerman and Hansen, 2000):
• edible offal for human consumption; • edible fats for shortening, margarine, sweets and chewing gum; • bone utilised in soup for human consumption, mixed with potter's clay, or the manufacture of buttons, knife handles and bone meal; • blood for human consumption and for animal feed, pharmaceuticals and food additives; • glycerin for numerous industrial uses, such as nitroglycerin, ointment bases, solvents, food preservatives and plasticisers; • intestines for sausage casings, the strings of musical instruments and surgical ligatures; • gelatin for confectionery items, ice cream and jellied food • rennin for cheese making; • numerous pharmaceutical products; • livestock feed (usually high in protein, fat and minerals); • pet food and feed for fish farming; • hides and skins for use as fur, leather or leather goods; • inedible fats for use in industrial products such as tyres, lubricants, insecticides and germicides; • hair for brushes, felt, rugs, upholstery, plaster binding and Edible offal for human consumption, such as liver, heart, kidney, tongue,sweetbread, brain and tripe is often processed at abattoirs. Processingof these materials is generally limited to trimming and rinsing. Thepreparation of animal intestines for use as sausage casings is a moreinvolved process, requiring emptying, de-sliming and cleaning.
Other edible by-products include cheeks, head trimmings, lungs, spinalcord, breast fat and stomachs and cattle paunches. These are commonlysent to other facilities for the manufacture of animal feed, including pet Cleaner Production Assessment in Meat Processing
food. The processing of these materials at abattoirs is generally limitedto cleaning in preparation for being sent off site.
Inedible by-products, such as fat, bones, hoofs, condemned offal anddead carcasses are rendered into tallow (derived from both cattle andsheep fat) or lard (derived from pig fat), and meat and bone meal. Tallowand lard have numerous applications and meat and bone meal are usedpredominantly as animal feed supplements. Rendering can take placeeither on site or at independent rendering plants.
In some regions, in particular the European Union, restrictions have beenplaced on the use of some animal by-products for human or animalconsumption. This has been due to outbreaks of Bovine SpongiformEncephalopathy (BSE), which is a fatal neurological disorder of adultcattle. In those areas where BSE is a concern, the use of dead carcassesfor the production of animal feed is prohibited, as is the use of the brainand spinal cord for human consumption.
Blood collected at abattoirs is a potentially valuable by-product. Blood isused in the formulation of food additives (emulsifiers, stabilisers,clarifiers, nutritional additives, egg albumin substitute), pharmaceuticals,fertilisers, animal feeds as well as in numerous industrial applications. Atabattoirs, blood is usually collected and stored in tanks and thentransported to specialised blood processing facilities.
Animal hide is one of the most valuable by-products from meatprocessing, since there are well–established markets for its use in mostparts of the world. Hides are converted into a variety of consumergoods, in particular shoes, bags and clothing. However other parts ofthe original hide can be recovered for use in the manufacture ofcosmetic ingredients and medical prosthetics. At abattoirs, hides may bechilled or salted and sent directly to the tannery. Alternatively, fleshingmay take place at abattoirs to recover the meat trimmings and fat fromthe hides before they are sent to the tannery.
2.2 Environmental impacts
As for many other food processing operations, the main environmental
issues associated with meat processing are the high consumption of
water, the discharge of high-strength effluent and the consumption of
energy. Noise, odour and solid wastes may also be issues for some
plants. Common environmental issues are summarised in Table 2—4.
Water consumption Hygiene standards necessitate the use of large quantities of fresh water.
Water is used for watering and washing livestock, cleaning processequipment and work areas and washing carcasses. Cleaning, inparticular, is a major area of water use.
One of the most obvious environmental issues common to all abattoirs isthe discharge of large quantities of effluent. Abattoir effluent containsblood, fat, manure, undigested stomach contents and cleaning agents. Itis typically characterised as having a high level of organic matter, fat,nitrogen, phosphorus and salt (sodium).
For plants located near urban areas, effluent may be discharged tomunicipal sewage treatment systems. This is the case in much ofEurope. However, in rural areas effluent is often treated on site andirrigated to land. Chapter 2 Overview of Meat Processing
If irrigation is not managed correctly, dissolved salts contained in theeffluent can adversely affect soil structure and cause salinity problems.
Nitrogen and phosphorus can also leach into underlying groundwaterand affect its quality.
In some locations effluent may be discharged directly into water bodies.
However this is generally discouraged as the high levels of organicmatter can deplete oxygen levels and thus degrade water quality.
Table 2—4 Environmental issues at abattoirs
Reception of livestock Effluent containing manure wastes High water consumption Stunning and bleeding Effluent with high organic load, especially ifblood is discharged Hide treatment (pigs) Energy consumption for hot water used inscalding Generation of putrescible by-products Effluent with a high content of organic matter Splitting and evisceration Energy consumption for equipment sterilisation Generation of putrescible by-products Effluent with high organic load High energy consumption Fugitive losses of refrigerants, e.g. CFCs orammonia Cutting and boning Electricity consumption Generation of putrescible by-products Energy consumption for equipment sterilisation Casing and offal processing Effluent with very high organic load Very high water consumption Effluent with very high organic load Potential for odour generation High energy consumption High water consumption Consumption of chemicals Large volumes of effluent with high organic load Cleaner Production Assessment in Meat Processing
Thermal energy, in the form of steam and hot water, is used for cleaningand sterilising and for rendering. Electricity is used for the operation ofmachinery and for refrigeration, ventilation, lighting and the productionof compressed air.
Like water consumption, the use of energy for refrigeration andsterilisation is important for ensuring good keeping quality of meatproducts. Storage temperatures are often specified by regulation. Aswell as depleting fossil fuel resources, the consumption of energycauses air pollution and greenhouse gas emissions, which have beenlinked to global warming.
By-products from the slaughter of livestock can cause environmentalproblems if not managed correctly. They are highly putrescible and cancause odour if not heat treated in a rendering process or removed fromsite within a day of being generated.
Dead stock and condemned carcasses must be disposed of in a way thatensures the destruction of all pathogenic organisms. All materials thatmay contain condemned parts are considered high-risk materials, andhave to enter an authorised rendering plant where proper sterilisationcan take place.
For small plants, the handling of animal by-products can be an importantwaste management issue. Smaller plants are often too small toeconomically undertake on-site rendering and may have difficulty insecuring access to rendering companies.
Air emissions Air emissions from meat processing plants are mostly attributed toenergy consumption. Steam, which is used for rendering and cleaningoperations, is generally produced in on-site boilers. Air pollutantsgenerated from combustion include oxides of nitrogen and sulphur andsuspended particulate matter.
Odour can be a serious problem for meat processing plants if by-products and effluent streams are not managed correctly, or if renderingtakes place on site. Biological treatment systems, commonly used totreat abattoir effluent, are another common source of odours.
Insufficient capacity of treatment systems or shock-loadings to thesystem can upset the microbiological balance of the system, resulting inthe release of hydrogen sulphide and other odorous compounds.
For operations that use refrigeration systems based onchlorofluorocarbons (CFCs), the fugitive loss of CFCs to the atmosphereis an important environmental consideration, since these gases arerecognised to be a cause of ozone depletion in the atmosphere. For suchoperations, the replacement of CFC-based systems with non- orreduced-CFC systems, such as ammonia, is important.
If an abattoir is located close to residential areas or other noise-sensitivereceptors, the noise generated from various items of equipment and themanoeuvring of trucks delivering livestock and removing by-products,can cause a nuisance. These potential problems should be taken intoconsideration when determining plant location.
Chapter 2 Overview of Meat Processing
2.3 Environmental indicators
Environmental indicators are important for assessing Cleaner Production
opportunities and for comparing the environmental performance of one
meat processing operation against another. They provide an indication of
resource consumption and waste generation per unit of production.
Environmental indicators for abattoir operations will vary according to
the size of plant, degree of utilisation of by-products, implementation of
Cleaner Production, climate and many other factors. Large variations are
typical, particularly for water, effluent and energy figures.
2.3.1 Water consumption
In abattoirs, water is used for numerous purposes, including:
• livestock watering and washing; • truck washing; • scalding and hide finishing of pigs; • washing of casings, offal and carcasses; • transport of certain by-products and wastes; • cleaning and sterilising of knives and equipment; • cleaning floors, work surfaces, equipment etc.; • make-up water for boilers; • cooling of machinery (compressors, condensers etc.).
Surveys of water consumption per unit of production consistently showconsiderable variation within the industry. A factor that affects waterconsumption is cleaning practices. Plants which produce meat for exportoften have stricter hygiene requirements and therefore may consumemore water for cleaning and sanitising.
Table 2—5 provides indicative figures for the breakdown of waterconsumption in abattoirs, based on Australian and Danish survey data.
Slaughter, evisceration and casings and offal processing tend to accountfor a large proportion of total water use, where it is used principally forcleaning.
Table 2—6 provides a summary of data from industry surveys describingwater consumption figures per unit of production. These figures arebased on a variety of production units, depending on the sourceliterature.
Cleaner Production Assessment in Meat Processing
Table 2—5 Breakdown of water consumption
Australian survey data1
Danish survey data2
Stockyard washdowns Livestock receipt and stock watering Slaughter, evisceration Casings processing Casings processing Inedible and edible offal Hair removal (pigs) Domestic-type uses Dressing (cattle) 1 MRC, 1995 (based on a survey of Australian abattoirs)2 Hansen and Mortesen, 1992 (based on a survey of Danish abattoirs) Table 2—6 Water consumption per unit of production
m3/t HSCW m3/t meat
Australia (1995) 2 Australia (1998) 3 1 Johns, 1993 (based on a literature review 1979–1993)2 MRC, 19953 MLA, 19984 Hansen and Mortensen, 19925 Hansen, 1997 Chapter 2 Overview of Meat Processing
2.3.2 Effluent discharge
The volume of effluent generated is a reflection of the volumes of water
used, since 80–95% of water used in abattoirs is discharged as effluent
(MRC, 1995). The remainder is held up with by-products and wastes or
lost through evaporation.
Meat processing effluents generally exhibit the following properties:
• high organic loads due to the presence of blood, fat, manure and undigested stomach contents; • high levels of fat; • fluctuations in pH due to the presence of caustic and acidic • high levels of nitrogen, phosphorus and salt; • high temperature.
The concentration of organic matter is a key indicator of effluent quality,and is commonly expressed as chemical oxygen demand (COD) or 5-daybiochemical oxygen (BOD5). Both of these indicators are widely used andthis document uses both, depending on the literature source.
Animal fats contained in abattoir effluent are long-chain fatty acids andglycerol, collectively referred to as fats, oils and greases. For simplicity,this document will refer to them as fats. Fats from animal sources aregenerally biodegradable and exhibit extremely high specific BOD5, morethan 2 g BOD5 per gram of lipid (Hrudey, 1984).
Nitrogen in abattoir effluent occurs mainly in the form of ammonia, dueto the breakdown of proteinaceous materials into amino acids and then,ammonia. However the nature of the ammonia species present dependson the pH. Therefore, nitrogen levels in abattoir effluent are commonlyexpressed as total nitrogen.
Pollutant concentrations in abattoir effluent can vary significantly fromone plant to the next, depending on the extent to which wastes areexcluded from the effluent stream. Table 2—7 provides indicative figuresfor the concentration of pollutants in effluent from pig, cattle and mixedspecies abattoirs.
Table 2—7 Average concentrations of pollutants in abattoir effluent 1
slaughtering 1 slaughtering 1
abattoirs 2
Suspended solids (mg/L) Total nitrogen (mg/L) Total phosphorus (mg/L) Oil and grease (fat) (mg/L) 1 Hansen and Mortensen, 19922 MRC, 1995 (based on a survey of Australian abattoirs) Cleaner Production Assessment in Meat Processing
Organic matter contained in abattoir effluent originates from all areas ofthe plant where water comes into contact with carcasses, manure, offaland blood etc. Of all the components of the abattoir effluent stream,blood constitutes the highest pollution load, followed by fat.
Blood is also the single most significant source of nitrogen in abattoireffluent. Therefore slaughter and evisceration areas as well as renderingplants, where blood processing takes place, contribute the most tonitrogen levels.
Phosphorus originates from manure and undigested stomach contents.
Blood processing within the rendering plant can also be a source ofphosphorus, if this process is practiced.
Salt (sodium) originates from manure and undigested stomach contents,and also from rendering and pickling processes. In some areas, the rawwater used in the plant can contribute towards high salt levels in theeffluent.
Fat in the effluent stream originates from trimmings that are allowed tofall to the floor, some of which will inevitably find its way into theeffluent stream. Fat can also originate from carcass washing.
It follows therefore that effluent quality depends on the extent to whichblood, fat, manure and undigested stomach contents are excluded fromthe effluent stream. In the case of blood and fat, allowing thesematerials to enter the effluent stream increases the cost of effluenttreatment and represents the loss of valuable products.
Another factor with an important bearing on effluent quality is whetherrendering occurs as part of a plant's operations. At those plants whererendering occurs, the rendering plant is generally the largest singlesource of effluent contamination. Rendering typically contributes about60% of a plant's total organic load but only 5–10% of the total volume(MRC, 1995).
Table 2—8 provides a typical breakdown of effluent loads generatedfrom different processing areas within abattoir operations in terms of thekey effluent contaminants.
Table 2—8 Breakdown of effluent loads for key contaminants in abattoir
Organic load
Casings processing Manure and paunch 1 MRC, 1995 (based on a survey of Australian abattoirs) Chapter 2 Overview of Meat Processing
In order to be a useful indicator of plant performance, effluent dischargeis expressed as pollutant load per unit of production. Table 2—9provides indicative figures for effluent pollutant loads generated per headof animal slaughtered (pig and cattle) and Table 2—10 provides figuresbased on tonne LCW and tonne HSCW.
Table 2—9 Pollution loads in abattoir effluent per head 1
(average 90 kg)
(average 250 kg)
Total nitrogen (kg/head) Total phosphorus (kg/head) Table 2—10 Pollution load in abattoir effluent per unit of production
(kg per tonne LCW)
(kg per tonne HSCW)
Soluble phosphorus Oil and grease (fat) 1 Ockerman and Hansen, 2000 (summary of survey data from US abattoirs) 2 Hansen and Mortensen, 1992 3 MRC, 1995 (survey of Australian abattoirs) 4 MLA, 1998 (survey of Australian abattoirs) 2.3.3 Energy consumption
Overall energy consumption will depend on the types of activities
occurring at an abattoir. For example rendering, if it occurs on site, will
add substantially to overall energy consumption. Pig scalding is an
energy-consuming process specific to pig abattoirs.
Approximately 80–85% of an abattoir's total energy need is for thermal
energy, in the form of steam or hot water, produced from the
combustion of fuels in on-site boilers.
Table 2—11 provides an indicative breakdown of thermal energy use in
an abattoir. The figures assume that rendering and pig scalding take
place as part of the operation.
Cleaner Production Assessment in Meat Processing
Table 2—11 Breakdown of thermal energy consumption 1
Percentage of total
Blood coagulation 1 Energy Authority of NSW, 1985 Fuel used for steam production in boilers is typically coal or fuel oil.
However the use of natural gas and liquid petroleum gas is increasingdue to environmental pressures to burn cleaner fuels. Fuel sources witha low sulphur content should be chosen in order to minimise sulphurdioxide emissions.
In some areas, abattoirs may be able to obtain heat energy from districtheating or steam from outside sources. It is also possible to recoverwaste heat from high-temperature rendering processes to heat water.
The remaining 15–20% of an abattoir's energy consumption is providedby electricity. Table 2—12 provides an indicative breakdown ofelectricity use in an abattoir. As can be seen, refrigeration accounts for asignificant proportion of electricity use.
Table 2—12 Breakdown of electricity consumption 1
Percentage of total
By-products processing 1 Energy Authority of NSW, 1985 To serve as a useful indicator of plant performance, energy use isexpressed per unit of production. Table 2—13 provides a summary ofdata from literature describing typical energy consumption in thoseterms.
Chapter 2 Overview of Meat Processing
Table 2—13 Energy consumption per unit of production
Total energy
Denmark (cattle) 2 Canada (cattle) 3 1 Meat and Livestock Australia, 1998 3 Ontario Ministry of the Environment, 1999 2.4 Benchmarks
A benchmark is a number that acts as a guide to the level of best
practice that is achievable in a specific area, for example environmental
performance. Often, suitable benchmarks are difficult to obtain and
difficult to use. However, when they are available they can be useful in
assessing the relative performance of a process or organisation.
Environmental indicators sometimes used by abattoirs to benchmark
performance are water consumption, energy consumption and the
organic load in effluent (COD or BOD5), expressed as figures per unit of
production. However, other indicators such as nitrogen and phosphorus
loads in effluent have also been used.
In some industries, environmental benchmarks are used extensively to
gauge the performance and competitiveness of a manufacturing process.
For the meat processing industry however, benchmarking of
environmental performance is not common and it is difficult to find
examples. The lack of environmental benchmarking is thought to be due
to the considerable variation in production processes and scales of
operation within the industry. The issue is further complicated by the
fact that there is no widely recognised standard unit of production. Units
used to describe production at abattoirs vary from country to country
and even within a country.
An additional problem is that existing benchmarks do not necessarily
relate to specific types of processes. For example, in order to compare
one process with another, or to compare a process with a specified
benchmark, the scale, age, efficiency and type of process should be
similar to enable sensible comparison.
It is recommended that companies should first establish environmental
benchmarks internally. It may then be possible to compare performance
with other similar organisations within the same state or country. From
there, the next step may be to compare performance with industries in
other countries as long as the factors contributing to those countries'
level of performance are understood.
Cleaner Production Assessment in Meat Processing
A selection of environmental benchmarks that have been established in anumber of countries is provided in Table 2—14. These figures should beused as a rough guide only.
Table 2—14 Examples of environmental benchmarks for abattoirs
Organic load in
cattle 1000 L/head pigs 180–230 L/head 500–900 MJ/ t DW cattle 800–1700 L/head 200–500 MJ/t DW mixed 12 kL/tHSCW 1 COWI, 1999 (based on best available technology) 2 Ontario Ministry of the Environment, 1999 3 Meat and Livestock Australia, 1998 Tables 2—15 and 2—16 provide examples of Denmark benchmarks thatrelate to the level of technology utilised. The levels of technology aredescribed as follows: • Traditional technology: medium to large abattoirs with low utilisation of installed capacity and no Cleaner Production (typicallyin developing countries and countries in transition); • Average technology: large abattoirs using minimal Cleaner Production methods (many Western countries); • Best available technology: industrial abattoirs with good utilisation of installed capacity, high throughput and good housekeeping.
Table 2—15 Benchmarks for pig abattoirs (90 kg pigs) 1
Heat and electricity kW.h/ animal Table 2—16 Benchmarks for cattle abattoirs (250 kg cattle) 1
Heat and electricity kW.h/ animal Chapter 3 Cleaner Production Opportunities
Meat processing typically consumes large quantities of water and
energy, discharges significant quantities of effluent and generates by-
products. For this reason, Cleaner Production opportunities described in
this guide focus on reducing the consumption of resources (water and
energy), increasing product yields and reducing the volume and pollutant
load of effluent discharges.
Although many processes in the food sector can be automated, it is
difficult to automate many of the processes within an abattoir because
of the irregular shape and weight of the animal carcasses. This means
that individual operators' practices have a significant impact on the
overall performance. Therefore, many of the Cleaner Production
opportunities described in this guide relate to housekeeping practices,
work procedures, maintenance regimes and resource handling, as
opposed to technological changes.
Section 3.1 provides examples of general Cleaner Production
opportunities that apply across the entire process, whereas Sections 3.2
to 3.11 present opportunities that relate specifically to individual unit
operations within the process. For each unit operation, a detailed
process description is provided along with Cleaner Production
opportunities specific to that process. Where available, quantitative data
for the environmental indicators applicable to each unit operation are
3.1 General
Many food processors that undertake Cleaner Production projects find
that significant environmental improvements and cost savings can be
derived from simple modification to housekeeping practices and
maintenance regimes. Table 3—1 contains generic housekeeping ideas
that apply to the process as a whole.
Table 3—1 Checklist of general housekeeping ideas 1
• Keep work areas tidy and uncluttered to avoid accidents.
• Maintain good inventory control of consumables, such as cleaning chemicals, packaging materials, food additives etc., to avoidwaste.
• Ensure that employees are aware of the environmental aspects of the company's operations and their personal responsibilities.
• Train staff in good cleaning practices.
• Schedule regular maintenance activities to avoid inefficiencies and 1 UNEP Cleaner Production Working Group for the Food Industry, 1999 3.1.1 Water consumption
Water is used extensively in meat processing, so water saving measures
are common Cleaner Production opportunities in this industry. The first
step is to analyse water use patterns carefully, by installing water
meters and regularly recording water consumption. Water consumption
data should be collected during production hours, especially during
Cleaner Production Assessment in Meat Processing
periods of cleaning. Some data should also be collected outside normalworking hours to identify leaks and other areas of unnecessary waste.
Water consumption data should be presented and discussed atmanagement meetings to formulate strategies for improved waterefficiency.
The next step is to undertake a survey of all process area and ancillaryoperations to identify wasteful practices. Examples might be hoses leftrunning when not in use, excessive flowrates, and so on. Installingautomatic shut-off equipment and flow restrictors, for example, couldprevent such wasteful practices. Automatic control of water use ispreferable to relying on operators to manually turn water off.
Once wasteful practices have been addressed, water use for essentialprocess functions can be investigated. It can be difficult to establish theminimum consumption rate necessary to maintain process operationsand food hygiene standards. The optimum rate can be determined onlyby investigating each process in detail and undertaking trials. Suchinvestigations should be carried out collaboratively by productionmanagers, food quality and safety representatives and operations staff.
When an optimum usage rate has been agreed upon, measures shouldbe taken to set the supply at the specified rate and avoid manualcontrol.
Once water use for essential operations has been optimised, water reusecan be considered. Wastewaters that are only slightly contaminatedcould be used in other areas. For example, defrost water fromrefrigeration systems and vacuum pump water is usually clean, andcould be reused for non-critical applications. Water used for carcasswashing could be recirculated. Wastewaters from the slaughter floor,washbasins, knife and implement sterilisers and carcass washing couldbe reused for gut cutting and washing. Treated effluent from on-siteeffluent treatment systems may be reused for stockyard washing, hidecleaning and livestock washing, as long as fresh water is used for thefinal livestock rinse. Some of these options may require screening,filtering or in-line bacterial control. It should also be noted that somewater reuse and recycle opportunities may be prohibited by someauthorities.
Wastewater reuse should not compromise product quality and hygiene,and reuse systems should be carefully installed so that reusedwastewater lines cannot be mistaken for fresh water lines, and anyreuse plans should be approved by all food safety officers.
The option to fully recycle treated effluent for use within the processmay become viable in the future, as effluent discharge quality standardsbecome tighter. As quality standards approach those of potable water,there will be a powerful incentive to take advantage of the investmentthat goes into effluent treatment. For this to occur however, treatmentprocesses would probably have to incorporate techniques such asmembrane filtration to remove dissolved solids. This would be necessaryto avoid progressive concentration of salts in the recycled water.
Table 3—2 is a checklist of common ideas for reducing waterconsumption. Many of these opportunities are discussed in more detaillater in this chapter.
Chapter 3 Cleaner Production Opportunities
Table 3—2 Checklist of water saving ideas 1
• Undertake dry cleaning of trucks prior to washing with water.
• Install high-pressure, low-volume spray nozzles.
• Use high pressure rather than high volume for cleaning surfaces.
• Use automatically operated scalding chambers rather than scalding tanks for the de-hairing of pigs.
• Use offal transport systems that avoid or minimise the use of • Use dry dumping techniques that avoid or minimise the use of water for the processing of cattle paunches and pig stomachs,instead of wet dumping techniques.
• Reuse relatively clean wastewaters from cooling systems, vacuum pumps etc., for washing livestock.
• Reuse final rinse waters from paunch and casings washing for other non-critical cleaning steps in the casings department.
• Reuse wastewaters from the slaughter floor, carcass washing, viscera tables and hand wash basins for the washing of inedibleproducts.
• Reuse cooling water from the singeing process for other application in the pig de-hairing area.
• Reuse the final rinse from cleaning operations for the initial rinse on the following day.
• Use dry cleaning techniques to pre-clean process areas and floors before washing with water.
• Use automatic control systems to operate the flow of water in hand wash stations and knife sterilisers.
1 UNEP Cleaner Production Working Group for the Food Industry, 1999 3.1.2 Effluent
Cleaner Production efforts in relation to effluent generation should focus
on reducing the pollutant load in effluents. The volume of effluent
generated is also an important issue. However this aspect is linked
closely to water consumption, so efforts to reduce water consumption
will also result in reduced effluent volumes. Opportunities for reducing
water consumption are discussed in the previous section.
Opportunities for reducing the pollutant load of abattoir effluent
principally focus on avoiding the discharge of polluting substances, such
as blood, undigested stomach contents, fat and scraps of meat, to the
effluent stream. This means capturing materials before they enter drains
and utilising dry cleaning methods wherever possible. Improvements to
cleaning practices are therefore where the most gains can be made.
Table 3—3 is a checklist of common ideas for reducing pollutant loads in
Since blood is one of the major sources of organic pollution for abattoirs,
its recovery is an important Cleaner Production initiative. Blood recovery
can decrease organic loads by approximately 40% (Jones, 1974).
Cleaner Production Assessment in Meat Processing
Table 3—3 Checklist of ideas for reducing effluent loads 1
• Maximise the segregation of blood by designing suitable blood collection facilities and allowing sufficient time for bleeding,typically seven minutes.
• Sweep up solid materials for use as by-products, instead of washing them down the drain.
• Fit drains with screens and/or traps to prevent solid materials from entering the effluent system.
• Use offal transport systems that avoid or minimise the use of • Use water sprays with a pressure of less than 10 bar for carcass washing to avoid removing fat from the surface.
• Use dry cleaning techniques to pre-clean process areas and floors before washing with water.
• Segregate high-strength effluent streams, such as rendering effluent and wastewaters from casings and paunch washing andtreat them separately.
1 UNEP Cleaner Production Working Group for the Food Industry, 1999 3.1.3 Energy
Energy is often an area where simple plant optimisation efforts can
provide substantial savings almost immediately with no capital
investment. Significant reductions can be made through simple
housekeeping and optimisation of existing processes. Additional savings
can be made through the use of more energy-efficient equipment and
heat recovery systems. Table 3—4 is a checklist of common ideas for
reducing energy consumption.
Table 3—4 Checklist of energy saving ideas 1
• Implement switch-off programs and install sensors to turn off or power down lights and equipment when not in use.
• Improve insulation on heating and cooling systems and pipework.
• Insulate and cover scald tanks.
• Recover waste heat from effluent streams, vents, exhausts and • Recover evaporative energy in the rendering process, using multi- effect evaporators.
• Maintain a leak-free compressed air system.
• Favour more efficient equipment.
• Improve maintenance to maximise energy efficiency of equipment.
• Maintain optimal combustion efficiencies on boilers.
• Eliminate steam leaks.
1 UNEP Cleaner Production Working Group for the Food Industry, 1999 Chapter 3 Cleaner Production Opportunities
In addition to reducing a plant's demand for energy, there areopportunities for using more environmentally benign sources of energy.
Opportunities include replacing fuel oil or coal with cleaner fuels, such asnatural gas, possibly purchasing electricity produced from renewablesources, or co-generation of electricity and heat on site. For some plantsit may also be feasible to recover methane from the anaerobic digestionof high-strength effluent streams to supplement fuel supplies.
3.1.4 By-products
Almost all animal by-products can potentially be used to produce a
useful commodity. It may not always be possible, however, to find
economic markets for all by-products. This will depend on the scale of
the operation, the cultural and culinary characteristics of the region and
the distance to suitable markets.
The ability to use all animal by-products to their full extent will often
depend on whether rendering facilities are available to convert inedible
components into useful products such as bone meal and tallow. Large
plants typically incorporate integrated on-site rendering and blood
processing facilities or generate sufficient material to be attractive for
off-site renderers.
Table 3—5 Checklist of ideas for maximising utilisation of by-products 1
• Segregate all by-products.
• Ensure that by-products are not contaminated with water or materials that would limit or prevent their reuse.
• Store by-products correctly to maintain quality and maximise the viability of reuse opportunities.
1 UNEP Cleaner Production Working Group for the Food Industry, 1999 3.2 Livestock reception
Animals are delivered to the abattoir in trucks, which are unloaded at thereception area. Trucks are generally washed and sometimes disinfectedbefore leaving the site.
Most abattoirs hold livestock on site for a period, typically1 to 2 days,prior to slaughter. During this period animals are usually fasted to reducethe quantity of stomach contents, thereby making cleaning of theintestines easier. Livestock for the following day's kill are held instockyards adjacent to the plant, whereas livestock being held for longerperiods may be grazed in paddocks around the plant.
Some plants may use holding periods to de-stress cattle, which helps toimprove final meat quality. Pigs are susceptible to heat stress andtherefore it is common for pig holding facilities to incorporate sprinklersystems, which spray water on the pigs to keep them cool, especially insummer. The water sprays can also assist in suppressing dust.
In some regions, bedding may be used in trucks and in holding yards foranimal welfare reasons and also to facilitate the collection of manure.
Prior to being slaughtered, livestock are also washed with water tominimise the amount of dirt and manure introduced to the plant.
Cleaner Production Assessment in Meat Processing
Inputs and outputs Figure 3—1 is a flow diagram showing the inputs and outputsassociated with livestock reception, and Tables 3—6 and 3—7 providedata on the key inputs and outputs for pig and cattle receptionrespectively.
Trucks containing Livestock reception Cleaning wastewaters Cleaned livestock Figure 31 Inputs and outputs for livestock reception
Table 36 Input and output data for the reception of a 100 kg pig
Water for cleaning Bedding (if used) Table 37 Input and output data for reception of 250 kg beef cattle
Water for cleaning Bedding (if used) Water is used for truck washing, cattle watering and washing andhosing out holding yards. Waste of water can occur due to overflowingdrinking troughs, leaking hoses and poor washing practices. Excessiveuse of water or poor containment of water can also lead to ponding ofwater in holding yards or paddocks. This can result in the need for extrawashing to remove accumulated mud from livestock.
The wastewaters generated from these activities contain manure andurine and therefore have a high organic load and solids content. Theyalso are a significant contributor to phosphorus loads.
Chapter 3 Cleaner Production Opportunities
Manure along with bedding can be a valuable source of nutrients andorganic carbon, but can also cause pollution problems if not used ordisposed of correctly.
Dirty livestock should be segregated on arrival and given a preliminary wash before joining the rest of the herd. This will reduce the amount ofwashing required for the herd as a whole.
Water troughs should be designed and located to avoid overflowing andproduction of muddy areas. They should be set on a concrete base andprotected from damage by livestock.
For truck washing, water should be used only after dry cleaning hasbeen undertaken. Using a high-pressure water supply and hoses fittedwith trigger nozzles will help reduce water consumption.
Manual cleaning of livestock should be restricted to those that need it. A20–35 mm diameter hose fitted with a 9–10 mm nozzle will maximiseefficiency. Large diameter hoses should be avoided as they arecumbersome and inefficient and nozzles are easily damaged (McNeil andHusband, 1995).
Recycled water from other areas of the plant, such as cooling systemsand vacuum pumps, can be use for washing trucks. Recycled watercould also be used for washing livestock. However for some markets,such as the European Union, the use of recycled water for stockwashing may be prohibited.
Wastewaters from truck and livestock washing should be screenedbefore being discharged to the effluent system. This will help reduce theloads of organic matter, suspended solids and also phosphorous enteringthe wastewater treatment system. Screening can best be achieved usingrotating screens or static run-down screens.
3.3 Stunning and bleeding
For pigs, stunning can be carried out by electric shock or byanaesthetisation with carbon dioxide. Mechanical stunning with a boltpistol is not often undertaken because of problems with skullpenetration. Electric stunning is carried out using a pair of tongs withtwo electrodes positioned behind the animal's ears. Carbon dioxideanaestetisation is undertaken by passing pigs through an atmospherecontaining about60–70% carbon dioxide. For cattle, concussion devices or bolt pistolsare the most commonly used stunning techniques.
After stunning, carcasses are shackled by the hind legs to a conveyor.
Bleeding, also referred to as sticking, takes place by cutting the cervicalvein and one of the arteries.
Bleeding is commonly undertaken using a hollow, sterilised knife, whichfeeds the blood to a collection facility. Blood accounts for about 5% ofthe live weight of beef cattle and pigs. However only about 70–80% ofthis is collected during bleeding, the remainder typically being lost to theeffluent stream.
The proportion collected will depend on the bleeding time. Time requiredfor effective bleeding is generally not less than seven minutes. Someblood loss continues during subsequent dressing operations—up to thepoint of hide removal, in the case of cattle.
Cleaner Production Assessment in Meat Processing
Inputs and outputs Figure 3—2 is a flow diagram showing the inputs and outputsassociated with the stunning and bleeding process, and Tables 3—8 and3—9 provide data for the key inputs and outputs for pigs and cattlerespectively.
Stunning and bleeding Carbon dioxide(CO2) Bled animal carcasses Figure 32 Inputs and outputs for stunning and bleeding
Table 38 Input and output data for the stunning and bleeding of a
100 kg pig

5 L Blood (assuming 80% 0.16 kg Wastewater BOD5 (blood loss) Table 39 Input and output data for the stunning and bleeding of
250 kg beef cattle

250 kg Bled cattle carcass 5 L Blood (assuming 80% BOD5 (blood loss) Chapter 3 Cleaner Production Opportunities
Of all the components present in abattoir effluent, blood constitutes thehighest pollution load. The bleeding area of the slaughter floor is themain source of blood contamination. Blood has a very high organiccontent, with its organic load equivalent estimated to be 0.14—0.18 kgBOD5 per kg. If it is discharged to the effluent stream, the effectivenessof any downstream effluent treatment system will be greatly affecteddue to the increased organic loads.
Blood is also the main contributor to nitrogen loads in effluent. This canhave serious implications for the disposal of the treated effluent, sincenitrogen is not readily removed in standard effluent treatment systems.
The release of treated effluents containing high levels of nitrogen cancause eutrophication problems downstream.
If collected blood is allowed to become contaminated with water, theeffectiveness of its subsequent processes is reduced. The presence ofwater reduces the efficiency of coagulation processes, and if the bloodis to be dried, increases the energy required to evaporate the watercontent.
After blood, fat is the next most important contaminant in effluentgenerated from the slaughter area. Fat blinds screens in the effluenttreatment system, resulting in the need for greater use of hot water toclean them.
Every effort should be made to maximise raw blood collection and its subsequent processing into blood meal or other value-added by-products. Blood recovery yields should be routinely assessed to checkthe effectiveness of the blood collection system.
Design of the bleeding area should ensure that all blood is directed tothe blood collection facility. Animals should not be bled until they arelocated over the blood collection facility and they should be allowed tobleed in this location for a minimum period of time, generally no lessthan about seven minutes (McNeil and Husband, 1995).
A shallow, inclined, stainless steel trough under the bleeding area,extending through to the hide removal area, is a suitable mechanism forcollecting blood. The trough should be elevated some distance abovefloor level to exclude cleaning water (McNeil and Husband, 1995).
Coagulated blood collecting in the trough will need to be scraped awayat regular intervals.
The most effective method of continuously recovering blood is a beltconveyor under the bleeding area. The belt should be troughed or haveside skirts to contain the blood and be fitted with scrapers to recoverblood from the conveyor. This type of system comes at the expense ofsome water consumption due to the requirement to clean the belt itself.
However fixed spray nozzles can provide efficient cleaning (McNeil andHusband, 1995).
To avoid cross contamination of blood and wastewater, two-way draindiversion systems can be used in the bleeding area. Two drain outletsare provided in the blood collection area, one to the blood tank and theother to the effluent system. During slaughtering, the outlet to theeffluent system is closed off so that all blood drains to the blood tank.
When slaughtering is finished, the outlet to the blood tank is closed andthe outlet to the effluent system is opened so that cleaning wastewatersare directed to the effluent system.
Cleaner Production Assessment in Meat Processing
Removable plugs or valves can be used to close off the outlets to thesedrains. Full-flow ball valves are preferred as they can be mechanicallyinterlocked so that as one valve opens, the other valve shuts. Control ofthe changeover of plugs or valves should be the responsibility of adesignated operator who also gives the go-ahead to start cleaning thearea.
Blood is highly perishable, therefore it should be chilled quickly andpromptly processed into value-added products. The investment requiredfor installation of a well-cooled storage tank and processing equipment ishigh, but necessary if the blood is to be sold as a by-product.
3.4 Hide treatment of pigs
The objective of surface treatment is to remove dirt and hair from pigcarcasses, prior to further processing. In some processes, skins may beremoved and sold for tanning. However skinning is usually restricted tothe slaughter of large sows for sausage manufacture or to small-scaleplants where the costs of scalding and dehairing equipment makes itprohibitive.
Carcasses are scalded with water at 60oC in a scald tank or in scaldingcabinets, to soften the skin in preparation for hair removal. Alkalinereagents may be added to the scald water to help remove the layer ofaccumulated oil, dirt and epidermal cells from the skin surface, makingthe skin whiter.
After scalding, hair is partly removed by manual shaving or for largeroperations, in de-hairing machines. Any remaining hair is singed with agas-fired hand-held torch or, for larger plants, by passing the carcassesthrough a singeing oven. The singeing operation may be followed byflushing with cold water. Any skin discolouration is then removed byscraping, either manually or in a scraping machine.
If the hide is to be removed, the surface is first cleaned by showeringand brushing, then the skin is loosened and pulled off. Fat is removedand the skins are salted or iced immediately and before being sold fortanning.
Inputs and outputs Figures 3—3 and 3—4 are flow diagrams showing the inputs andoutputs for the dehairing and hide removal processes respectively. Table3—10 provides input and output data for the more common dehairingprocess.
Dehairing of pigs Figure 33 Inputs and outputs for dehairing of pigs
Chapter 3 Cleaner Production Opportunities
Figure 34 Inputs and outputs for skinning pigs
Table 310 Input and output data for the dehairing of a 100 kg pig
(if used instead of oil) Water consumption can be high, especially for the de-hairing processand for cooling after singeing.
Wastewaters from this process contain high levels of organic matter, fatand dirt. In particular, wastewaters from scald tanks or from in-linescalding cabinets can have temperatures of up to 75oC. If they aredischarged while hot they will melt fat and allow it to pass through theprimary effluent screening system. This increased loading of fat willcause problems for downstream effluent treatment systems.
The process consumes a lot of energy, particularly for heating water andfor operating singeing ovens.
If scalding tanks are used, they should be insulated and covered by a lid to avoid heat and evaporation losses. This will save both energy andwater. The payback period depends on the existing heat losses, butshould be 1–2 years.
To reduce water consumption for cleaning of the scalding tank, the tankbottom should have a steep gradient towards the outlets. Thewastewater should pass through a sedimentation tank, interceptor trapor sand trap before discharge. The investment required is high, but thesemeasures should be considered when replacing an existing scaldingtank.
Cleaner Production Assessment in Meat Processing
Water consumption for de-hairing can be minimised by applying water
only as required and ensuring that water pressure and the number,
placement and size of water nozzles are optimal.
There are also a number of opportunities for water reuse in this area.
Cooling water can be collected in a tank and reused for other purposes,
such as water sprays in the de-hairing machines. Boiler condensate can
also be used as make-up water for the scalding tank.
Automatically operated scalding chambers use less water than scalding
tanks. Using such systems, water consumption can be reduced by
50–70%. The investment required is high, and the payback period may
be more than 5 years.
The de-hairing process results in substantial quantities of hair collecting
on the floor where it can enter the drainage system. Strainers should be
fitted to floor drain outlets to collect the hair and avoid blockages.
The singeing oven must be insulated and provided with automatic doors
that close during singeing. If not, significant energy is lost. Payback on
investment for insulation and automatic doors will be at most one year.
Gas consumption in singeing ovens can be reduced by using solenoid
switches to initiate the singeing flame only when carcasses are passing
through and to regulate flame intensity in line with line speed.
Overhead rails in singeing ovens are sometimes cooled using cold water.
In these situations, the consumption of cooling water can often be much
greater than necessary. Installing thermometers to measure the
temperature of cooling water can allow flow to be regulated to the
minimum required.
Case study 31: Reducing water consumption for pig de-hairing
At a pig abattoir, water consumption for dehairing, singeing, scrapingand brushing amounted to 141 L/pig before the water-savingcampaign began. By reducing the water pressure and installing on–offregulation controlled by the carcass conveyor, consumption wasreduced to 96 L/pig, a 32% reduction. The next step was to collect allcooling water from the singeing oven and use it in the other machinesinstead of disposing of it. In addition, the trickling system in the hidetreatment machines was replaced with nozzles which give a well-defined direction and angle of spray. This resulted in a furtherdecrease in water consumption from 96 to 26 L/pig, a 73% reduction.
The investment for a slaughter line treating up to 400 pigs per hourwas about US$33,000, resulting in a saving of US$0.2–0.3/pig,depending on water and wastewater charges.
(Hansen and Mortensen, 1992) Chapter 3 Cleaner Production Opportunities
3.5 Hide removal and dressing of cattle
Prior to hide removal, the head, hoofs, feet and tail are removed. Insome smaller operations, hides may be removed manually. However, inmedium to large plants hide removal is generally performedmechanically. Most hide removal equipment is either pneumatically orhydraulically powered. Electrical stimulation is often applied to ‘stiffen'the carcass during the hide-pulling operation.
Before hides can be processed further at a tannery, the flesh must beremoved and the hides washed and immersed in brine. The fleshingprocess may take place at the abattoir, thereby recovering the fleshingsfor rendering, or at the tannery. If they are to be sent to the tannerywithout fleshing, hides are packed unwashed in salt. Fleshings are madeup of fat and flesh and represent about 15% of the weight of the hide.
The cattle hide accounts for 5—9% (average 7%) of the live weight ofbeef cattle (Ockerman and Hansen, 2000). Consequently it is one of themost valuable by-products from beef cattle.
Inputs and outputs Figure 3—5 is a flow diagram showing the inputs and outputs from thisprocess, and Table 3—11 provides data for the key inputs and outputs.
Salted or chilled Hide removal anddressing of cattle Figure 35 Inputs and outputs for hide removal and dressing of cattle
Table 311 Input and output data for hide removal and dressing of

Bled cattle carcass 238 kg Dehided cattle carcass Head, hoofs, tail etc.
When hides are preserved by salting, saturated brine or salt crystals areused. Up to 4 litres of saturated brine can be lost for each hide treated.
These spent brine solutions can pose substantial disposal problems.
Cleaner Production Assessment in Meat Processing
A typical consumption of salt for conserving hides is about 350 kg per tonne of hide. However, if hides are to be stored for 6 weeks or less,salt use can be reduced to 150 kg per tonne of hide. If a biocide isadded, the consumption of salt can be further reduced to 50 kg pertonne.
Reduced salt consumption would also be advantageous for the receivingtannery, since many tanneries experience problems with too much salt intheir wastewater.
3.6 Evisceration and splitting
The objective of evisceration is to remove the edible organs, theintestinal tract (casings) and the thoracic cavity (pluck). For pigs, thehead is also removed as part of this process.
Edible organs consist of the liver and kidneys etc., and the intestinaltract consists of the stomach (or paunch in the case of cattle), intestinesand spleen. The pluck materials consist of the heart, esophagus, lungsand trachea.
Offal, casings and pluck materials are collected in trolley bins (for smalloperations), or on a moving-top viscera table (for larger operations) andthen transferred to other areas of the plant for further processing.
The carcasses are split into two using saws and knives, and thentrimmed and graded. This is followed by washing, either manually usinghoses or in automated carcass washing units.
Finally, the carcasses are sent for chilling or directly to the boning areafor further processing. Carcasses are chilled to temperatures between0.5oC and 1.5oC for at least 24 hours.
Inputs and outputs Figure 3—6 is a flow diagram showing the inputs and outputs from thisprocess, and Tables 3—12 and 3—13 provide data for the key inputs and outputs for pigs and beef cattle respectively.
Slaughtered animal Various trimmings, fats and other by-products Two half carcasses Figure 36 Inputs and outputs for evisceration and splitting
Chapter 3 Cleaner Production Opportunities
Table 312 Input and output data for the evisceration and splitting of a
100 kg pig

Dehaired pig carcass 93 kg Split pig carcass 40 L Intestinal tract Plucks and edible organs Table 313 Input and output data for the evisceration and splitting of
250 kg beef cattle

207 kg Split cattle carcass 100 L Plucks and edible organs Evisceration and splitting are generally undertaken without water.
However large amounts of hot water (82oC) are used for the cleaningand sterilisation of knives and equipment (saws, trays, gambrels, hooks,rails etc).
Carcass washing can be a significant source of water waste and effluentcontamination. In manual operations there is a tendency for operators touse more water than is necessary. In contrast, in automated carcasswashing units sprays are activated only when a side of meat is in thewashing cabinet. The amount of water used can be set to the minimumrequired.
Water pressures greater than 10 bar for carcass washing can remove fatfrom the surface. This fat contributes to high oil and grease levels in theeffluent stream. Water temperatures greater than 30°C can further exacerbate fat loss.
The use of water for cooling and transport of by-products results in highwater consumption and high organic content in the effluent.
By-products should be transported dry on conveyors or in small containers with wheels. Container systems are a cheap and easysolution, whereas conveyors can be very expensive to install.
Cleaner Production Assessment in Meat Processing
If water sprays are to be used on conveyor systems, variable-speeddrives and flow-control valves should be used to regulate water flow asthe conveyor speed alters.
The pressure of water sprays used for carcass washing should be lessthan 10 bar and cool water should be used to reduce the removal of fatfrom the surface of the carcass.
If carcasses are chilled in chill tanks, the rate of water discharge fromthe tanks should be reduced to the minimum level required to maintainacceptable bacterial counts. In addition, counter-current flow systemshould be used on chill tanks.
3.7 Casings processing
The term ‘casings' refers to the intestinal tract of the animal or gut set.
For pigs, it consists of the stomach, small and large intestines, middlecap, bladder and bung. For cattle the casings consist of the stomach(paunch, honeycomb, bible and rennet), bladder, small intestine, middleintestine and bung.
Certain parts of the casings can be processed into a number of value-added products, such as sausage skins, surgical sutures and strings formusical instruments and tennis rackets. Processing of casings involvesde-sliming to remove the inner lining ‘mucosa‘, and washing.
If casings are not processed into value-added products, they aregenerally sent for rendering with or without prior washing.
Inputs and outputs Figure 3—7 is a flow diagram showing the inputs and outputs from thisprocess and Tables 3—14 and 3—15 provide data for the key inputs andoutputs for the processing of casings from pigs and cattle respectively.
Casings processing Figure 37 Inputs and outputs for casings processing
Table 314 Input and output data for the processing of one set of pig

Chapter 3 Cleaner Production Opportunities
Table 315 Input and output data for processing of one set of beef
cattle casings

Water consumption for casings processing is very high, and can be upto 20% of total water consumption in plants where it is undertaken.
Casings processing can also be a significant contributor to the organicand fat load in the effluent stream.
Fasting of animals for a period of 12 to 24 hours prior to slaughter reduces the quantity of undigested materials in the intestinal tract,making the evisceration process easier.
Since the water consumption and effluent loads generated by thisprocess can be considerable, an assessment should be made of whethercasings cleaning is a profitable choice. It may be better to send theempty intestines for inedible rendering, especially if water resources arescarce and the wastewater is poorly treated.
Water from the final rinse of the casings could be collected andrecirculated or used for cleaning the large intestines and bungs. Thiswould require a collection vessel and pipework.
If casings are to be washed for rendering only, recycled water from theslaughter floor, carcass washing, viscera tables and hand wash basinscould be used, as it is still of high quality. To prevent blockages ofnozzles or jets, the water should first be screened to remove grosssolids (McNeil and Husband, 1995).
New techniques for emptying gut sets from pigs, without the use ofwater, have been developed in Denmark. Pig stomachs are conveyedover a rotating slitting blade and the stomach contents fall into a chute.
Whether this option is feasible depends on the cost of water and thecharges on wastewater.
3.8 Paunch washing (cattle)
In ruminants (cattle, sheep etc.), the paunch or first stomach contains a
large amount of undigested material, referred to as paunch manure. Forcattle, it is estimated that about 36–45 kg of wet paunch material isproduced per head, but this depends on the size of the cattle beingslaughtered and their history.
In some plants paunches are slashed, emptied and washed with water(wet dumping), so that edible products can be recovered from thepaunch. Alternatively, paunches can be emptied and sent, withoutwashing (dry dumping), to be rendered or used in pet food production.
Wet-dump systems generate 145–390 L effluent per paunch processed,whereas dry-dump systems generate 7–19 L effluent per paunch(MIRINZ, 1996). In the dry-dump system however, the paunch sack isnot used as an edible by-product, due to the residual contamination withpaunch manure.
Cleaner Production Assessment in Meat Processing
Paunch manure is usually collected as a separate stream and screened toremove solids. Screened paunch solids are a good source of nutrientsand are often applied to land or composted. The screened effluent isgenerally sent to the effluent treatment plant along with other effluentstreams. At some plants the entire paunch manure stream is sent to theeffluent treatment plant, but this practice is becoming less common ascompanies attempt to reduce the organic loads entering treatmentplants.
Inputs and outputs Figure 3—8 is a flow diagram showing the inputs and outputs from thisprocess and Table 3—16 provides data for the key inputs and outputs.
Paunch processing Figure 38 Inputs and outputs for paunch processing
Table 316 Input and output data for paunch processing
50 kg Washed cattle paunch 200 L1 Paunch manure 1 This applies to wet-dump systems In plants where paunch washing takes place, water consumption in thecasing process can be very high.
Paunch manure contains high concentrations of organic solids and otherpollutants. BOD5 concentrations have been estimated to be about50,000 mg/L (Baumann, 1971). If paunch manure is discharged to aneffluent treatment plant, problems can arise due to the resultant hightotal solids concentration. The undigested solids are not easily degradedin biological treatment systems and build up as sludge in the system,reducing its overall treatment capacity.
Chapter 3 Cleaner Production Opportunities
Fasting animals for a period of 12 to 24 hours prior to slaughtering reduces the quantity of paunch material, making the evisceration process
Since the water consumption and effluent loads generated by this
process are considerable, an assessment should be made of whether
paunch washing is a profitable choice.
As with casings processing, use may be made of recycled water from
other parts of the plant.
For cattle, a technique which allows for the recovery of the paunch
sack, while reducing water consumption and effluent loading, is the two-
step dry dump/spray wash system. The paunches are first emptied of
their contents, without the use of water, and then rinsed using an
efficient water spray system. See case study below.
Case study 32: Reduced effluent generation in paunch wash system
A survey was undertaken in New Zealand at five beef processingplants to evaluate different paunch handling operations and to trial atwo-step dry dump/spray wash system.
It was found that the two-step system reduced water consumptionand the pollutant load of the effluent stream, while allowing thepaunch sack to be used as an edible by-product.
It was estimated that converting a wet-dump system to a two-stepsystem could reduce the total effluent loading of a typical beefabattoir by 18–33% for total solids, 16–31% for COD, 9–18% fortotal nitrogen and 20–46% for total phosphorus. Potentially, theconversion could reduce a plant's effluent treatment or disposal costsby a similar proportion.
Paunch manure from cattle is an ideal medium for composting orvermiculture (worm composting) along with other waste materials. Aftercomposting it can be used or marketed as a fertiliser and soilconditioner. Under some circumstances, paunch manure may be spreaddirectly onto agricultural land; however prior composting is preferable.
Rendering is an essential part of the meat processing industry. Renderingconverts highly perishable meat by-products that are unfit for humanconsumption into useful commodities such as meat meal, bone meal,tallow and also pet food. Materials that are commonly rendered includeinedible offal and fat from the slaughtering process, dead animals andanimal that have been classed as ‘condemned' as a resulted of the postslaughter inspection.
Cleaner Production Assessment in Meat Processing
The basic aims of rendering are: • Sterilisation to make products safe; • Recovery of fat to make the meal suitable for milling and stabilise ti against oxidation; and • Drying, to prevent bacterial growth and to facilitate transportation and storage.
Rendering is carried out using a number of different systems rangingfrom simple batch cooking systems in which fat is removed by hydraulicpresses to highly sophisticated continuous systems. Pre-crushed rawmaterials are loaded into the rendering cooker. The material is heated tohigh temperatures, which evaporates the water and sterilises it. Fat isallowed to drain from the mixture in a percolator pan and the remainderof the fat is pressed out mechanically, either in a hydraulic press (batchprocess) or continuously in a screw press. The press cake is milled toproduce meat meal and bone meal and the fat is further refined toremove impurities, by precipitation, centrifugation etc.
Inputs and outputs Figure 3—9 is a flow diagram showing the inputs and outputs from atypical small rendering process. Table 3—17 provides data for the keyinputs and outputs.
Rendering materials Sterilisation and Heat and electricity Meat and bone meal Figure 39 Inputs and outputs for rendering
Chapter 3 Cleaner Production Opportunities
Table 317 Input and output data for rendering
Raw materials (offal, 1000 kg1 Bone meal dead animals, etc.) Fuel oil for steam 70 kW.h Wastewater Water for condenser 200–500 L Total nitrogen Water for cleaning 1 Approximately 60% of the weight of the raw materials is water, which ends up as condensate wastewater as a result of the rendering process.
Water consumption for rendering is relatively low with a usage rate ofabout 1m3/tonne raw material and typically represents less than 10% oftotal water use at an abattoir.
Effluent from the rendering plant contains very high loads of organicmatter, and at those plants where it is undertaken rendering is thelargest single source of effluent contamination. Rendering effluentcomprises condensate from dry rendering, stickwaters from wetrendering, decanters and blood coagulation and from polishercentrifuges.
The energy consumption for rendering is very high, especially for thedrying step. However modern systems can be quite energy efficient,especially when multiple effect evaporators are used.
Rendering materials are highly putrescible, and if not handled and treatedcorrectly can cause extremely bad odours. The exhaust fumes from therendering process are also extremely odourous. It is often necessary toinstall odour control systems to reduce odour emissions to withinrequired limits.
Since the rendering process converts ‘waste' materials into useful, value-added products, rendering in itself is a Cleaner Production option.
Raw materials for rendering should be received at the rendering plant assoon as possible, and processed promptly to avoid odour. Delays inprocessing result in poor quality raw materials which lead to loweryields, lower quality products, and difficulties in processing the rawmaterials. Rendering materials should also be kept cool on ice, at about10–15°C or preferably lower.
The heat contained in the vapour from the cookers can also berecovered in multiple effect evaporators etc. and used to pre-heat rawmaterials. This can reduce energy consumption from about 60 kg to 35–40 kg oil per tonne of raw material.
The effluent stream from rendering along with other high-strengthstreams, such as that from paunch and stomach dumping, could becollected and treated separately. By treating these streams separatelyfrom the low-strength streams from the rest of the plant, overalltreatment performance is improved. Segregated, high-strength effluent Cleaner Production Assessment in Meat Processing
streams could be anaerobically digested to produce methane-rich biogas.
The biogas could be used to supplement energy supplies on site.
All work areas and equipment are cleaned daily, usually at the end ofeach production shift. A common cleaning regime is as follows. First,equipment and floors are roughly hosed down. Then detergents andfoam are applied, followed by washing and scrubbing. The detergentsnormally used are alkaline to remove fat and protein. The detergents anddirt are removed by hosing and/or scraping. Finally, there is a rinse withclean water to remove all detergent or disinfectant.
Areas that have high levels of fat residues such as boning and cuttingrooms require high-pressure, low-volume water at approximately 60oC togive the most economical water usage. Higher water temperature willincrease the amount of steam vapour and associated condensationproblems, without any increase in cleaning efficiency (McNeil andHusband, 1995).
As well as the major cleaning that occurs at the end of each shift, knivesand some items of equipment are washed and sterilised frequentlythroughout production. Hygiene regulations usually require that knivesbe sterilised in hot water and that the water in the sterilisers be replacedat set frequencies. Operators also regularly wash their hands. Knifesterilisers and hand wash stations are located at work-stations onslaughter floors and in processing areas for this purpose.
Hand basins provide a flow of hot water (35–43oC) at about 15 L/min(McNeil and Husband, 1995). The flow is controlled by thigh or pedaloperated mechanisms; however microprocessor controlled units are alsoused. Knife sterilisers can be bowl-type or spray-type systems. Bowl-type sterilisers contain hot water that is continuously replenished tomaintain the required temperature of about 82oC.
Inputs and outputs Figure 3—10 is a flow diagram showing the inputs and outputs from thisprocess.
Dirty equipment and floors Clean equipment and floors Figure 310 Inputs and outputs for cleaning
Cleaning is one of the most water-intensive operations at abattoirs,typically accounting for 20–25% of total water consumption.
Wastewater from cleaning contains a high organic load, as well asdetergents and disinfectants.
Chapter 3 Cleaner Production Opportunities
The best way to reduce water consumption in cleaning is to undertake dry cleaning before washing with water. Solid materials should first be
scraped and swept from all surfaces, including boning, slicing and
packing tables, cutting boards, work platforms and floors.
Case study 33: Proper work procedures and control of water
consumption in cleaning

Changes in cleaning practices at a pig abattoir resulted in a 31%reduction in water consumption and a 67% reduction in the use ofdetergents, without impairing hygiene. Undertaking dry cleaning toremove solid materials from floors and equipment prior to washingalso resulted in a 30% decrease in overall man-hours used for thecleaning operations. The investment was low and water savingamounted to 10 litres per pig. This is a saving of US$0.02–0.03 perpig. Labour costs and costs for cleaning agents were alsosubstantially reduced.
Industrial vacuum cleaners have been used successfully in boning roomsfor dry cleaning operations at abattoirs. Solids may have to be loosenedand scraped free from surfaces, before the vacuum cleaner can be usedto collect the solids for transfer to a rendering plant (McNeil andHusband, 1995).
Case study 34: Collection of waste from floors with a vacuum cleaner
Experiments have shown that collection of waste materials from floorsin the slaughter, bleeding and evisceration areas using a vacuumcleaner can reduce wastewater loads by 50 g BOD5 per pig. Theinvestment required is approximately US$25,000. The annual savingsdepend largely on costs for discharge of wastewater and surchargesfor pollution load, but can amount to US$4000–37,000 per year.
After thorough dry cleaning, work surfaces, walls and floors can bewashed down in preparation for cleaning with detergents. The followingmeasures will help reduce water consumption for this step: • Hoses should be fitted with spray nozzles, since a pressurised spray is far more effective for cleaning surfaces and therefore usesless water. A pressure of 25–30 bar is advisable.
• Flat-jet nozzles should be used to provide maximum impact and velocity. Spray angles of up to 60o provide wide coverage and asweeping effect to propel solids towards floor drains.
• The first rinse should be with cold water, because warm water will make protein materials stick to the surfaces. The temperature ofthe water for the subsequent cleaning depends on the kind ofcontamination. Cold water is often sufficient.
• The wastewater from the final rinse can be collected and used for the initial rinse on the following day.
Detergents and disinfectants can be a significant source of pollution ifthe amounts used are too great. It is very important, therefore, tomonitor their consumption.
Cleaner Production Assessment in Meat Processing
The following measures will help reduce detergent consumption: • Determine the required amount or concentration for effective • Use a set concentration of detergents so that detergent use reduces as water consumption reduces; • Use new detergents, some of which are more effective and more environmentally friendly than older ones. Alternative detergentsshould be evaluated on the basis of their cleaning performance aswell as their cost and environmental attributes.
Sanitisers should be applied as a fine spray to cleaned surfaces, ratherthan as a final rinse with hot water. Chemical sanitisers can be moreeffective in bacteriological control, less damaging to the building andsafer for personnel than large quantities of hot water (McNeil andHusband, 1995).
Spray nozzles, commonly used for cleaning operations, are subject towear that causes deterioration of the orifice and distortion to the spraypattern. This results in an increased flowrate of water and reducedeffectiveness. In general, 10% nozzle wear will result in a 20% increasein water consumption (McNeil and Husband, 1995). Nozzles made fromdifferent materials have varying abrasion resistance, as shown inTable 3—18.
Regular monitoring of spray nozzle wear should be incorporated intomaintenance programs. Nozzles in service can be compared with newnozzles to determine the extent of wear. The flowrate of a nozzle can bedetermined by measuring the time taken to fill a container of knownvolume.
Table 3—18 Abrasion wear index for nozzle materials 1
Abrasion wear index
90–200 (excellent) 1 McNeil and Husband, 1995 Microprocessor-controlled hand wash stations, which use an infraredbeam to initiate the flow of water for a pre-set period help overcome theproblem of water wastage that can sometimes occur when operators tiedown the controls of manually operated units.
Double-skin insulated knife steriliser bowls use less water thanconventional bowl-type sterilisers, since they minimise heat loss andtherefore reduce the rate of overflow required to maintain the requiredtemperature. For a 3-litre bowl, this can mean an overflow rate of 15L/hr compared with 36 L/hr for conventional bowl sterilisers. (McNeiland Husband, 1995).
For spray-type knife sterilisers, continually running sprays should beavoided and the flow should be initiated only when the implement isintroduced into the unit and the sprays should run for a pre-set period oftime. Control of steriliser flow rates should be the responsibility of adesignated person and flow rates should be checked regularly.
Chapter 3 Cleaner Production Opportunities
3.11 Ancillary operations
3.11.1 Compressed air supply
Air is compressed in an air compressor and distributed throughout theplant in pressurised pipes. Usually, compressors are electrically poweredand cooled with water or air.
Figure 3—11 is a flow diagram showing the inputs and outputs from thisprocess.
Used compressor oil Compressed air supply Warm coolling water Compressed air to equipment Figure 3—11 Inputs and outputs for production of compressed air
Even a few small holes in the compressed air system (pipes, valvesetc.), result in the loss of a large amount of compressed aircontinuously. This results in a waste of electricity because thecompressor has to run more than is necessary. Table 3—19 listsunnecessary electricity consumption that can be caused by leaks in acompressed air system.
Table 3—19 Electricity losses from compressed air system leaks (6 bar)
Hole size (mm)
Air losses (L/s)
Air compressors are often very noisy, and can be a nuisance for noise-sensitive receptors in some circumstances. If the air compressor is watercooled, water consumption can be quite high.
It is very important to check the compressed air system frequently. The best method is to listen for leaks during periods when there is noproduction. Maintenance (e.g. change of compressor oil) and the keepingof accurate logbooks will often help identify the onset of system leaks.
Shutting the system off when not in use and reducing the operatingpressure of the system can also reduce the use of compressed air.
A temperature-sensitive valve, ensuring the optimum coolingtemperature and minimum use of water should regulate the consumptionof cooling water. Furthermore, cooling water can be recirculated via a Cleaner Production Assessment in Meat Processing
cooling tower. Alternatively, the cooling water can be reused for otherpurposes such as cleaning, where hygiene requirements are low.
Case study 3—5: Reuse of air compressor cooling water
An air-cooling system for an air compressor was replaced with awater-cooled one. The water absorbs the heat from the compressorand is then reused in the boilers. Energy is saved in the boilersbecause the water is preheated.
The installation of the water cooling system cost US$18,000 andprovided a payback period of less than two years.
3.11.2 Steam production
Steam is produced in a boiler and distributed throughout the plantthrough insulated pipes. Condensate is returned to a condensate tank,from where it is recirculated as boiler feed water, unless it is used forheating in the production process.
The amount and pressure of the steam produced depends on the size ofthe boiler and how the fuel is injected into the combustion chamber.
Other parameters include pressure, fuel type, maintenance and operationof the boiler.
Inputs and outputs Figure 3—12 is a flow diagram showing the inputs and outputs from thisprocess.
Boiler feed water make-up and condensate return (90°C) Figure 3—12 Inputs and outputs for supply of steam
Inefficiencies in boiler operation and steam leaks lead to the waste ofvaluable fuel resources as well as additional operating costs.
Combustion of fuel oil results in emissions of carbon dioxide (CO2),sulphur dioxide (SO2), nitrogen oxides (NOx) and polycyclic aromatichydrocarbons (PAHs). Some fuel oils contain 3–5% sulphur and result insulphur dioxide emissions of 50–85kg per 1000 litres of fuel oil.
Sulphur dioxide converts to sulphuric acid in the atmosphere, resulting inthe formation of acid rain. Nitrogen oxides contribute to smog and cancause lung irritation.
Chapter 3 Cleaner Production Opportunities
If the combustion is not adjusted properly, and if the air: oil ratio is toolow, high emissions of soot can result. Soot contains PAHs that arecarcinogenic.
Table 3—20 shows the emissions produced from the combustion ofvarious fuels to produce steam.
Table 3—20 Emissions from the combustion of fuel oil
Fuel oil (1% sulphur) 1 kg Energy content 1 kg of oil = 1.16 litre of oil (0.86 kg/L)1 kW.h = 3.6 MJ Oil is often spilt at the oil storage area and at the boiler. If the spilt oil isnot collected and reused or sold, it can cause serious pollution of soiland water.
Although most condensate from steam systems is returned to the boiler,some fresh water make-up is required. For inefficiently operated boilers,the amount of feed water required can be excessive. As well as higherwater consumption, this results in the need to add additional boilerchemicals and increased fuel consumption to preheat the feed water.
Instead of using fuel oil with high sulphur content, it is advantageous to change to a fuel oil with a low sulphur content—less than 1%. This willincrease the efficiency of the boiler and reduce the emission of sulphurdioxide. There are no investment costs related to this option, but therunning costs will be higher because the fuel oil with a lower sulphurcontent is more expensive.
It is essential to avoid oil spills and, if they do occur, to clean them upproperly and either reuse or sell the oil. A procedure for handling oil andoil spills should be prepared and followed.
If the boiler is old, the installation of a new one should be considered.
Changing from coal to oil, or from oil to natural gas, should also beconsidered. In some burners is it possible to install an oil atomiser andthereby increase efficiency. When purchasing a new boiler, emphasisshould be placed on purchasing the minimum sized boiler that issufficient to meet the steam demand of the plant. Purchasing an over-sized boiler for the sake of contingency may not really be necessary.
Insulation of hot surfaces is a cheap and very effective way of reducingenergy consumption. Equipment such as valves, flanges, autoclaves,heated vessels and pipe connections to machinery should be insulated:Proper insulation of these surfaces can reduce heat loss by 90%. Thepayback period for insulation is often less than 3 years.
The way in which a boiler is operated will affect its efficiency. If theair:fuel ratio is wrongly adjusted burning will be poor, causing morepollution and less efficient utilisation of the fuel. Proper operation of theboiler requires appropriate training of employees and, if the expertise isnot available within the company, and possibly frequent visits ofspecialists.
Cleaner Production Assessment in Meat Processing
Condensate return to the boiler should be maximised to minimise waterconsumption and improve boiler efficiency. If condensate from someareas is not returned to the boiler, piping systems to return it should beinstalled. Steam trap performance should be monitored regularly toensure efficient return of condensate and to ensure they are not leaking.
Case study 3—6: Poorly operated coal-fired boiler
Samples of coal and waste ash were taken from coal-fired boilers andwere measured for specific energy (kJ/kg), ash percentage andmoisture percentage. Results showed that up to 29% of the total fuelsupply was not being combusted in the boilers, with the least efficientboiler generating an additional 230 kg of unburnt material per tonne ofcoal. This unburnt material was retained in the ash and disposed of inlandfill.
To improve performance, the company trained employees in efficientboiler operation, so that boilers could be run on automatic control.
After this training, boiler efficiency increased by 25%, and the specificenergy of the ash reduced to 6 kJ/kg.
Coal use was reduced by 1500 tons, making an annual saving ofUS$45,000. Improved boiler operation also reduced annual landfilldisposal by 275 tonnes. The company hired a specialist company tomonitor boiler efficiency on an ongoing basis. The cost of this serviceis US$2100 per month.
3.11.3 Water supply
High-quality domestic water supplies may not need any treatment beforeuse in the plant, however if the available water is of poor quality it maybe necessary to treat it to meet hygiene requirements. Treatmentnormally consists of aeration and filtration through gravel or sand, andchlorination may also be necessary.
Inputs and outputs Figure 3—13 is a flow diagram showing the inputs and outputs from thisprocess.
private water supply Figure 3—13 Inputs and outputs for supply of water
Chapter 3 Cleaner Production Opportunities
Water is a valuable resource so its use should be minimised whereverpossible. Since electricity is needed for pumping water, energyconsumption also increases with increasing water consumption.
The losses that occur due to holes in water pipes and running taps canbe considerable. Table 3—21 shows the relationship between size ofleaks and water loss.
Table 3—21 Water loss from leaks at 4.5 bar pressure 1
Hole size (mm)
Water loss (m3/day)
Water loss (m3/year)
To ensure that water consumption is optimised, usage rates should be monitored on a regular basis. It is helpful to install water meters forseparate departments and even for individual processes or pieces ofequipment. Whether this is feasible depends on the level of waterconsumption and the expected savings in each instance. Waterconsumption can be reduced by 10–50% simply by increasingemployees' awareness and by educating them on how to reduceunnecessary consumption.
Energy-efficient pumps should be installed to reduce the energyconsumed for pumping of water. New and efficient pumps can reduceenergy consumption by up to 50% compared with standard pumps. It isvery important to select a pump with optimum pumping capacity andposition it close to the required work area.
3.11.4 Refrigeration and cooling
In refrigeration and cooling systems a refrigerant, typically ammonia or achlorofluorocarbon (CFC)-based substance, is compressed, and itssubsequent expansion is used to chill a closed circuit cooling system.
The refrigerant itself can act as a primary coolant, recirculated directlythrough the cooling system, or alternatively, it can be used to chill asecondary coolant, typically brine or glycol.
CFCs were once extensively used in refrigeration systems, but they arenow prohibited in many countries, and their use is being phased out as aresult of the Montreal Protocol on ozone-depleting substances. Allcooling systems should be closed circuit systems and free of leaks.
However, due to wear and tear and inadequate maintenance, leaks mayoccur.
Cleaner Production Assessment in Meat Processing
Inputs and outputs Figure 3—14 is a flow diagram showing the inputs and outputs from thisprocess.
Warm spirit/glycol Spirit/glycol losses Old compressor oil Cold spirit/glycol Figure 3—14 Inputs and outputs for cooling system
The consumption of electricity and of water can be quite high.
If CFC-based refrigerants are used there is a risk that refrigerant gaseswill be emitted to the atmosphere, contributing to the depletion of theozone layer. There is also a risk of ammonia and glycol leaks, which canbe an occupational, health and safety problem for workers, and can alsoresult in environmental problems.
CFC-based refrigerants should be replaced by the less hazardous hydrochlorofluorocarbons (HCFCs) or, preferably, by ammonia. In thelong run both CFCs and HCFCs should be replaced by other refrigerantsaccording to the Montreal Protocol. Replacing CFCs can be expensive,as it may require the installation of new cooling equipment.
Minimising the ingress of heat into refrigerated areas can reduce energyconsumption. This can be accomplished by insulating cold rooms andpipes that contain refrigerant, by closing doors and windows to coldareas, and by installing self-closing doors.
If water and electricity consumption in the cooling towers seems high, itcould be due to algal growth on the evaporator pipes. Another reasoncould be that the fans are running at too high a speed, blowing thewater off the cooling tower.
Chapter 4 Cleaner Production Case Study
This case originates from a Cleaner Production assessment carried out at
a Danish pig abattoir. It describes what the company did and what the
assessment achieved. The description below follows the Cleaner
Production assessment procedure as described in Chapter 5.
4.1 Phase I: Planning and organisation
Obtain management The company wanted to reduce water consumption, because the costs of water and disposing of wastewater were too high.
Set up a project team The management formed a project team, which comprised a foreman, atechnical engineer and an external consultant.
The company did not have a formal environmental policy; however, its strategy was to reduce water consumption and pollution withoutimpairing product quality.
Plan the Cleaner The project team decided to focus the Cleaner Production assessment on the pig reception and holding areas. An assessment of the slaughter linehad been undertaken previously. The following steps were decided upon: • inspection of the area; • measurement of water consumption; • assessment of the work procedure; • development of a list of possible improvements.
4.2 Phase II: Pre-assessment
Describe the process The project team first described the processes that take place in thereception and holding areas. The abattoir processes about 1.1 millionpigs per year. The pigs are delivered in trucks, each containing 50–60pigs. Each truck must be cleaned and disinfected after unloading,according to regulations. The cleaning procedure takes place in asegregated cleaning area. Approximately 75 trucks are cleaned everyworking day.
During the site inspection the following points were noted regarding the site inspection cleaning of trucks: • Sawdust is used as bedding in the trucks.
• The driver removes the bedding and manure using water hoses with 10 mm nozzles.
• The waste is washed to drains and very little is collected.
• Afterwards the driver cleans the truck carefully, using cold water.
The site inspection revealed the following problems: • High consumption of water.
• Running hoses.
• Discharge of manure and sawdust bedding to the sewer, causing high organic loading in the effluent.
Plan assessment phase The project team decided to continue with the assessment of thereception area, since the pre-assessment had shown a considerable Cleaner Production Assessment in Meat Processing
number of opportunities for Cleaner Production improvements. In reality,the project team did not distinguish between work in the pre-assessmentphase and in the assessment phase.
4.3 Phase III: Assessment
Collect data The team measured water consumption by measuring the time it took tofill a container of known volume. Readings from a water meter supplyingwater to a larger area were taken to verify the data collected manually.
The following data were collected: • Water consumption was approximately 17 L per pig or 950 L per • The water pressure was approximately 12 bar.
• The quantity of solid organic waste generated was not measured, neither was the organic pollution load of the effluent.
Identify Cleaner The project team discussed ways of reducing water consumption and minimising the organic load of the wastewater. The following optionswere identified: • Using water at a pressure higher than 12 bar and using smaller • Removing the bedding with a scraper before washing with water;• Reducing the amount of sawdust bedding in the trucks;• Training employees to reduce the losses.
These options were discussed further in the evaluation phase.
4.4 Phase IV: Evaluation and feasibility study
As the number of options was limited, the project team could quickly assess them. Reducing the amount of bedding would not give significantreductions in water consumption and pollution. It was therefore decidedto focus on the other options.
During the technical evaluation it was found that it was desirable and feasible to increase the water pressure from 12–18 bar, and at the sametime change from the 10 mm nozzles to a trigger-controlled, jet spraygun.
The technical evaluation also showed that the dry collection of beddingand manure (i.e. before washing) would require the construction of anew area where the trucks could park, so that the bedding could bescraped directly into an automatic solid waste removal system. Theproject team inspected an existing area that was not in use, and foundthat it would be suitable for this purpose.
The team estimated the costs of changing to high-pressure jet sprays and found that it would be feasible since only a minor investment wasrequired. No large investments were required for the dry collection ofbedding and manure, so the most important issue was whether it wouldrequire more labour to carry out the dry cleaning as well as wetcleaning. A trial showed that the dry cleaning and wet cleaning could bedone as quickly as the previous method. The total investment inequipment and installation was estimated to be US$5000.
Chapter 4 Cleaner Production Case Study
Undertake environmental The project team expected that implementing the options would bringevaluation about a 50% reduction in water consumption and a similar reduction inorganic load of the effluent.
Select options The project team presented the four options to the manager. It wasdecided to implement them all and to train the employees and truckdrivers in the new procedures.
4.5 Phase V: Implementation and continuation
Prepare an action plan After the meeting with the manager, an implementation plan was drawnup. The plan took into account the time required for training theemployees and drivers, without disrupting normal production. Staffresponsible for the various options were appointed.
The following options were implemented: • Bedding and manure were collected dry in a separate area by scraping them into a solid waste storage container. The wastewas composted and later applied to land as fertiliser.
• Hoses were equipped with trigger-controlled spray guns and the water pressure was increased to 18 bar. Each gun deliveredapproximately 60 L of water per minute.
• The drivers were instructed in the proper use of the equipment and made aware of the importance of saving water and reducingpollution.
As part of the implementation process, a monitoring program wasestablished to document improvements. The new cleaning operation wasevaluated and figures for water consumption and pollution wererecorded. The results were as follows: • Water consumption was reduced to 5.6 L per pig (67% reduction).
• BOD was reduced to 13 g per pig.
• Solid organic waste was reduced to 1.4 kg per pig.
• Man-hours required for the cleaning of trucks remained The savings for the abattoir were nearly 12 L of potable water per pig.
Based on a cost of US$2 per KL, which includes the cost of water andcharges for disposal of the wastewater, the annual savings areapproximately US$24,000. The extra costs for pressurising water andtransporting the manure and bedding have not been included in thiscalculation.
4.6 Contacts
For more information on this case please contact:
Poul-Ivar E. Hansen
Danish Meat Research Institute
Maglegaardsvej 2
DK-4000 Roskilde, Denmark
Chapter 5 Cleaner Production Assessment
A Cleaner Production assessment is a methodology for identifying areasof inefficient use of resources and poor management of wastes, byfocusing on the environmental aspects and thus the impacts of industrialprocesses.
Many organisations have produced manuals describing CleanerProduction assessment methodologies at varying levels of detail.
However, the underlying strategies are much the same. The basicconcept centres around a review of a company and its productionprocesses in order to identify areas where resource consumption,hazardous materials and waste generation can be reduced. Table 5-1lists some of the steps described in the more well-known methodologies.
Table 5-1 Methodologies for undertaking a Cleaner Production assessment
UNEP, 1996
Guidance Materials for the UNIDO/UNEP National Cleaner 2. Pre-assessment 4. Evaluation and feasibility study 5. Implementation and UNEP, 1991
Audit and Reduction 1. Pre-assessment Manual for Industrial Emissions and Wastes. 2. Material balance Technical Report Series Dutch Ministry of
PREPARE Manual for the Prevention of Waste and Emissions 4. Implementation USEPA, 1992
1. Development of Prevention Guide 2. Preliminary assessment The rest of this chapter describes the steps within a Cleaner Productionassessment as outlined in the UNEP/UNIDO document, GuidanceMaterials for UNIDO/UNEP National Cleaner Production Centres. (UNEP,1995). The steps from this methodology are detailed further inFigure 5—1.
Cleaner Production Assessment in Meat Processing
See section 5.1 Phase I: Planning and organisation ž Obtain management commitment ž Establish a project team ž Develop policy, objectives and targets ž Plan the Cleaner Production assessment See section 5.2 Phase II: Pre-assessment (qualitative review) ž Company description and flow chart ž Walk-through inspection ž Establish a focus See section 5.3 Phase III: Assessment (quantitative review) ž Collection of quantitative data ž Material balance ž Identify Cleaner Production opportunities ž Record and sort options See section 5.4 Phase IV: Evaluation and feasibility study ž Preliminary evaluation ž Technical evaluation ž Economic evaluation ž Environmental evaluation ž Select viable options See section 5.5 Phase V: Implementation and continuation ž Prepare an implementation plan ž Implement selected options ž Monitor performance ž Sustain Cleaner Production activities Figure 5—1 Overview of the Cleaner Production assessment methodology (UNEP, 1996)
Chapter 5 Cleaner Production Assessment
5.1 Planning and organisation
The objective of this phase is to obtain commitment to the project,
initiate systems, allocate resources and plan the details of the work to
come. A project has more chance of success if this groundwork is done
Planning and
• Strategy• Objectives• Targets Work plan
Figure 5—2 Planning and organisation phase
5.1.1 Obtain management commitment
Experience from companies throughout the world shows that Cleaner
Production results in both environmental improvements and better
economic performance. However, this message has to reach the
management of the company. Without management commitment the
Cleaner Production assessment may be only a short-term environmental
management tool.
5.1.2 Establish a project team
It is best to establish a project team as early in the process as possible.
The project team is responsible for progressing the assessment and will
normally undertake the following tasks:
• analysis and review of present practices (knowledge); • development and evaluation of proposed Cleaner Production • implementation and maintenance of agreed changes (authority).
5.1.3 Develop environmental policy, objectives and targets
The environmental policy outlines the guiding principles for the
assessment. It acts to focus efforts in a way considered most important
by management. The environmental policy can be refined as the project
team gains more insight into the Cleaner Production possibilities within
the company.
The policy contains the company's mission and vision for continuous
environmental improvement and compliance with legislation. Objectives
describe how the company will do this. For example, objectives could
include reducing consumption of materials and minimising the generation
of waste. Targets are measurable and scheduled, and are used to
Cleaner Production Assessment in Meat Processing
monitor if the company is proceeding as planned. An example of a targetmight be a 20% reduction in electricity consumption within 2 years.
In general, objectives and targets should be: • acceptable to those who work to achieve them; • flexible and adaptable to changing requirements; • measurable over time (targets only); • motivational; • in line with the overall policy statement.
5.1.4 Plan the Cleaner Production assessment
The project team should draw up a detailed work plan and a time
schedule for activities within the Cleaner Production assessment.
Responsibilities should be allocated for each task so that staff involved
in the project understand clearly what they have to do. It is also wise to
anticipate any problems or delays that may arise and plan for them
accordingly. Lengthy delays and problems arising out of poor planning
erode motivation at both the worker and management level.
5.2 Pre-assessment
The objective of the pre-assessment is to obtain an overview of the
company's production and environmental aspects. Production processes
are best represented by a flow chart showing inputs, outputs and
environmental problem areas.
5.2.1 Company description and flow chart
A description of the company's processes should answer the following
• What does the company produce? • What is the history of the company? • How is the company organised? • What are the main processes? • What are the most important inputs and outputs? Processes which take place as part of the company's activities can berepresented using a detailed process flow chart. Flow chart production isa key step in the assessment and forms the basis for material andenergy balances which occur later in the assessment. Process flowcharts should pay particular attention to activities which are oftenneglected in traditional process flow charts, such as: • cleaning;• materials storage and handling;• ancillary operations (cooling, steam and compressed air • equipment maintenance and repair;• materials that are not easily recognisable in output streams (catalysts, lubricants etc.); • by-products released to the environment as fugitive emissions.
Chapter 5 Cleaner Production Assessment
The process flow chart is meant of providing an overview and shouldthus be accompanied by individual input/output sheets for each unitoperation or department. Figure 5—3 provides an example of aninput/output worksheet, however it may be arranged in various ways.
Ancillary materials: Short description: Hazardous materials: health and safety: Wastewater discharge: Figure 5—3 Example of an input/output worksheet
5.2.2 Walk-through inspection
Much of the information needed to fill out the input/output sheets,
described above, may be obtained during a walk-through inspection of
the company.
The walk-through inspection should, if possible, follow the process from
the start to the finish, focusing on areas where products, wastes and
emissions are generated. During the walk-through, it is important to talk
to the operators, since they often have ideas or information that can be
useful in identifying sources of waste and Cleaner Production
opportunities. The text box over page provides examples of the types of
questions that may be asked to prompt the investigation.
During the walk-through problems encountered along the way should be
listed, and if there are obvious solutions to these they should also be
noted. Special attention should be paid to no-cost and low-cost
solutions. These should be implemented immediately, without waiting
for a detailed feasibility analysis.
5.2.3 Establish a focus
The last step of the pre-assessment phase is to establish a focus for
further work. In an ideal world, all processes and unit operations should
be assessed. However time and resource constraints may make it
necessary to select the most important aspect or process area. It is
common for Cleaner Production assessments to focus on those
processes that:
• generate a large quantity of waste and emissions;• use or produce hazardous chemicals and materials;• entail a high financial loss;• have numerous obvious Cleaner Production benefits;• are considered to be a problem by everyone involved.
Cleaner Production Assessment in Meat Processing
All the information collected during the pre-assessment phase should bewell organised so that it is easily accessed and updated.
Questions to be answered during a walk-through inspection
Are there signs of poor housekeeping (untidy or obstructed work areas
Are there noticeable spills or leaks? Is there any evidence of past spills,
such as discoloration or corrosion on walls, work surfaces, ceilings and
walls, or pipes?
Are water taps dripping or left running?
Are there any signs of smoke, dirt or fumes to indicate material losses?
Are there any strange odours or emissions that cause irritation to eyes,
nose or throat?
Is the noise level high?
Are there open containers, stacked drums, or other indicators of poor
storage procedures?
Are all containers labelled with their contents and hazards?
Have you noticed any waste and emissions being generated from
process equipment (dripping water, steam, evaporation)?
Do employees have any comments about the sources of waste and
emissions in the company?
Is emergency equipment (fire extinguishers etc.) available and visible to
ensure rapid response to a fire, spill or other incident?
5.3 Assessment
The aim of the assessment phase is to collect data and evaluate the
environmental performance and production efficiency of the company.
Data collected about management activities can be used to monitor and
control overall process efficiency, set targets and calculate monthly or
yearly indicators. Data collected about operational activities can be used
to evaluate the performance of a specific process.
Chapter 5 Cleaner Production Assessment
List of problems and solutions
AREA (company or department) Problem description Figure 5—4 Assessment phase
5.3.1 Collection of quantitative data
It is important to collect data on the quantities of resources consumed
and wastes and emissions generated. Data should be represented based
on the scale of production: for example: water consumption per tonne of
live carcass weight (LCW) processed or mass of organic matter (COD)
generated per tonne of live carcass weight (LCW) processed. Collection
and evaluation of data will most likely reveal losses. For instance, high
electricity consumption outside production time may indicate leaking
compressors or malfunctioning cooling systems.
In determining what data to collect, use the input/output worksheets,
described previously, as a guide. Most data will already be available
within the company recording systems, e.g. stock records, accounts,
purchase receipts, waste disposal receipts and the production data.
Where information is not available, estimates or direct measurements
will be required.
5.3.2 Material balance
The purpose of undertaking a material balance is to account for the
consumption of raw materials and services that are consumed by the
process, and the losses, wastes and emissions resulting from the
process. A material balance is based on the principle of ‘what comes
into a plant or process must equal what comes out'. Ideally inputs
should equal outputs, but in practice this is rarely the case, and some
judgment is required to determine what level of accuracy is acceptable.
A material balance makes it possible to identify and quantify previously
unknown losses, wastes or emissions, and provide an indication of their
sources and causes. Material balances are easier, more meaningful and
more accurate when they are undertaken for individual unit operation.
An overall company-wide material balance can then be constructed with
The material balance can also be used to identify the costs associated
with inputs, outputs and identified losses. It is often found that
Cleaner Production Assessment in Meat Processing
presenting these costs to management can result in a speedyimplementation of Cleaner Production options.
While it is not possible to lay down a precise and complete methodologyfor undertaking a material balance, the following guidelines may beuseful: • Prepare a process flow chart for the entire process, showing as many inputs and outputs as possible.
• Sub-divide the total process into unit operations. (Sub-division of unit operations should occur in such a way that there is thesmallest possible number of streams entering and leaving theprocess).
• Do not spend a lot of time and resources trying to achieve a perfect material balance; even a preliminary material balance canreveal plenty of Cleaner Production opportunities.
Environmental performance indicators for the process can be developedfrom the material balance data. This is achieved by dividing the quantityof a material input or waste stream by the production over the sameperiod. Performance indicators may be used to identify over-consumption of resources or excessive waste generation by comparingthem with those of other companies or figures quoted in the literature.
They also help the company track its performance towards itsenvironmental targets.
5.3.3 Identify Cleaner Production opportunities
Identifying Cleaner Production opportunities depends on the knowledge
and creativity of the project team members and company staff, much of
which comes from their experience. Many Cleaner Production solutions
are arrived at by carefully analysing the cause of a problem.
Another way of identifying Cleaner Production opportunities is to hold a
‘brainstorming' session, where people from different parts of the
organisation meet to discuss solutions to specific problems in an open
and non-threatening environment.
Some other sources of help from outside the organisation could be:
• this guide;• external industry personnel or consultants;• trade associations;• universities, innovation centres, research institutions, government • equipment suppliers;• information centres, such as UNEP or UNIDO;• literature and electronic databases.
5.3.4 Record and sort options
Once a number of Cleaner Production opportunities have been suggested
and recorded, they should be sorted into those that can be implemented
directly and those that require further investigation.
Chapter 5 Cleaner Production Assessment
It is helpful to follow the following steps: • Organise the options according to unit operations or process areas, or according to inputs/outputs categories (e.g. problemsthat cause high water consumption).
• Identify any mutually interfering options, since implementation of one option may affect the other.
• Opportunities that are cost free or low cost, that do not require an extensive feasibility study, or that are relatively easy to implement,should be implemented immediately.
• Opportunities that are obviously unfeasible, or cannot be implemented should be eliminated from the list of options forfurther study.
Table 5—2 Example of information recorded for identified options
Problem type
• name of process • how the problem • short background • short-term solution • long-term solution • air pollution materials lost or • money lost due to • hazardous waste health and safety 5.4 Evaluation and feasibility study
The objective of the evaluation and feasibility study phase is to evaluate
the proposed Cleaner Production opportunities and to select those
suitable for implementation.
The opportunities selected during the assessment phase should all be
evaluated according to their technical, economic and environmental
merit. However, the depth of the study depends on the type of project.
Complex projects naturally require more thought than simple projects.
For some options, it may be necessary to collect considerably more
information. An important source of this information may be employees
affected by the implementation.
Cleaner Production Assessment in Meat Processing
Figure 5—5 Evaluation and feasibility study phase
5.4.1 Preliminary evaluation
The quickest and easiest method of evaluating the different options is to
form a group, consisting of the project team and management personnel,
and discuss the possible solutions one by one. This process should give
a good indication of which projects are feasible and what further
information is required.
5.4.2 Technical evaluation
The potential impacts on products, production processes and safety
from the proposed changes need to be evaluated before complex and
costly projects can be decided upon. In addition, laboratory testing or
trial runs may be required when options significantly change existing
practices. A technical evaluation will determine whether the opportunity
requires staff changes or additional training or maintenance.
5.4.3 Economic evaluation
The objective of this step is to evaluate the cost effectiveness of the
Cleaner Production opportunities. Economic viability is often the key
parameter that determines whether or not an opportunity will be
When performing the economic evaluation, costs of the change are
weighed against the savings that may result. Costs can be broken into
capital investments and operating costs. Standard measures used to
evaluate the economic feasibility of a project are payback period, net
present value (NPV), or internal rate of return (IRR).
Capital investment is the sum of the fixed capital costs of design,
equipment purchase, installation and commissioning, costs of working
capital, licenses, training, and financing. Operating costs, if different to
existing conditions will need to be calculated. It may be that operating
costs reduce as a result of the change, in which case, these should be
accounted for in the evaluation as an ongoing saving.
5.4.4 Environmental evaluation
The objective of the environmental evaluation is to determine the
positive and negative environmental impacts of the option. In many
cases the environmental advantages are obvious: a net reduction in
toxicity and/or quantity of wastes or emissions. In other cases it may be
necessary to evaluate whether, for example, an increase in electricity
consumption would outweigh the environmental advantages of reducing
the consumption of materials.
Chapter 5 Cleaner Production Assessment
For a good environmental evaluation, the following information isneeded: • changes in amount and toxicity of wastes or emissions; • changes in energy consumption; • changes in material consumption; • changes in degradability of the wastes or emissions; • changes in the extent to which renewable raw materials are used; • changes in the reusability of waste streams and emissions; • changes in the environmental impacts of the product.
In many cases it will be impossible to collect all the data necessary for agood environmental evaluation. In such cases a qualified assessment willhave to be made, on the basis of the existing information.
Given the wide range of environmental issues, it will probably benecessary to prioritise those issues of greatest concern. In line with thenational environmental policy of the country, some issues may have ahigher priority than others.
Aspects to be considered in the evaluation
Preliminary evaluation

• Is the Cleaner Production option available? • Can a supplier be found to provide the necessary equipment or • Are consultants available to help develop an alternative? • Has this Cleaner Production opportunity been applied elsewhere? If so, what have been the results and experience? • Does the option fit in with the way the company is run?
Technical evaluation
• Will the option compromise the company's product? • What are the consequences for internal logistics, processing time and production planning? • Will adjustments need to be made in other parts of the company? • Does the change require additional training of staff and employees?
Economic evaluation
• What are the expected costs and benefits? • Can an estimate of required capital investment be made? • Can an estimate of the financial savings be made, such as reductions in environmental costs, waste treatment costs, materialcosts or improvements to the quality of the product? • What is the expected environmental effect of the option? • How significant is the estimated reduction in wastes or emissions? • Will the option affect public or operator health (positive or negative)? If so, what is the magnitude of these effects in terms oftoxicity and exposure? Cleaner Production Assessment in Meat Processing
5.4.5 Select options
The most promising options must be selected in close collaboration with
management. A comparative ranking analysis may be used to prioritise
opportunities for implementation. The concept of such a method is
shown below in Table 5-3. An option can be assigned scores, say from
1 to 10, based on its performance against a set of evaluation criteria. By
multiplying each score by a relative weight assigned to each criterion, a
final score can be arrived at. The options with the highest scores will
probably be best suited for implementation. However, the results of this
analysis should not be blindly accepted. Instead, they should form a
starting point for discussion.
All simple, cost-free and low-cost opportunities should of course be
implemented as soon as possible.
Table 5-3 Example of a weighted sum method for evaluating alternative options
Reduced hazardous waste treatment Reduced wastewater treatment costs Reduced amount of solid waste Reduced exposure to chemicals Reduced amount of water consumption Reduced odour problems Reduced noise problems Easy to install and maintain * -3 = lowest rank, 0 = no change, +3 = highest rank (preferred) 5.5 Implementation and continuation
The objective of the last phase of the assessment is to ensure that the
selected options are implemented, and that the resulting reductions in
resource consumption and waste generation are monitored continuously.
Chapter 5 Cleaner Production Assessment
Figure 5—6 Implementation and continuation phase
5.5.1 Prepare an implementation plan
To ensure implementation of the selected options, an action plan should
be developed, detailing:
• activities to be carried out; • the way in which the activities are to carried out; • resource requirements (finance and manpower); • the persons responsible for undertaking those activities; • a time frame for completion with intermediate milestones.
5.5.2 Implement selected options
As for other investment projects, the implementation of Cleaner
Production options involves modifications to operating procedures and/or
processes and may require new equipment. The company should,
therefore, follow the same procedures as it uses for implementation of
any other company projects.
However, special attention should be paid to the need for training staff.
The project could be a failure if not backed up by adequately trained
employees. Training needs should have been identified during the
technical evaluation.
5.5.3 Monitor performance
It is very important to evaluate the effectiveness of the implemented
Cleaner Production options. Typical indicators for improved performance
• reductions in wastes and emissions per unit of production;• reductions in resource consumption (including energy) per unit of • improved profitability.
There should be periodic monitoring to determine whether positivechanges are occurring and whether the company is progressing towardits targets. Examples of the types of aspects that could be checked toevaluate improvements are shown in Table 5-4.
Cleaner Production Assessment in Meat Processing
5.5.4 Sustain Cleaner Production activities
If Cleaner Production is to take root and progress in an organisation, it is
imperative that the project team does not lose momentum after it has
implemented a few Cleaner Production options. Sustained Cleaner
Production is best achieved when it becomes part of the management
culture through a formal company environmental management system or
a total environmental quality management approach.
An environmental management system provides a decision-making
structure and action plan to support continuous environmental
improvements, such as the implementation of Cleaner Production.
If a company has already established an environmental management
system, the Cleaner Production assessment can be an effective tool for
focusing attention on specific environmental problems. If, on the other
hand, the company establishes a Cleaner Production assessment first,
this can provide the foundations of an environmental management
Regardless of which approach is undertaken, Cleaner Production
assessment and environmental management systems are compatible.
While Cleaner Production projects have a technical orientation, an
environmental management system focuses on setting a management
framework, but it needs a technical focus as well.
To assist industry in understanding and implementing environmental
management systems, UNEP, together with the International Chamber of
Commerce (ICC) and the International Federation of Engineers (FIDIC),
has published an Environmental Management System Training Resource
. This kit is compatible with the ISO 14001 standard.
Like the Cleaner Production assessment, an environmental management
system should be assessed and evaluated on an ongoing basis and
improvements made as required. While the specific needs and
circumstances of individual companies and countries will influence the
nature of the system, every environmental management system should
be consistent with and complementary to a company's business plan.
Chapter 5 Cleaner Production Assessment
Table 5—4 Evaluation checklist
Overall Cleaner Production assessment check
• Are the opportunities implemented according to the action plan? • Are new procedures being followed correctly by the employees? • Where do problems occur and why? • Do licenses or permits require amendments? Which ones? • Has compliance with legislation been maintained as a result of the changes? Environmental performance check
• Are the opportunities cost effective? Is the cost effectiveness as expected? • Has the number of waste and emission sources decreased? By how many? • Has the total amount of waste and emissions decreased? By how much? • Has the toxicity of the waste and emissions decreased? By how much? • Has the energy consumption decreased? By how much? • Have the Cleaner Production goals been achieved? Which have and which • Have there been any technical ramifications? Which and why? Documentation check (The following items should be included in the files.)
• Statements of the company's objectives and targets and the environmental • Company description and flow diagram with input and outputs • Worksheets completed during the Cleaner Production assessment • Material balances • List of Cleaner Production opportunities generated during brainstorming • Lists of opportunities that are technically, economically and environmentally • Implementation action plan • Monitoring data • ‘Before-and-after' comparisons • Post-implementation evaluation reports Annex 1 References and Bibliography
Baas, L. W., van der Belt, M., Huisingh, D. and Neumann, F., 1992. Cleaner
Production: What some governments are doing and what all governments can do to promote sustainability. European Water Pollution Control 2(1).
Baumann, D. J., 1971. Elimination of water pollution by packinghouse animal
paunch and blood. USEPA Water Pollution Control Research Series, Report 12060 FDS 11/71.
COWI Consulting Engineers and Planners AS, Denmark, 1999. Internal data.
Danish Environmental Protection Agency (Danish EPA), 1995. Branch
Consultancy Service concerning Cleaner Technology in Pig Slaughterhouses. Working Report No 17, (in Danish).
Danish Environmental Protection Agency (Danish EPA), 1996. Environmental
Information System for Meat Processing Industry. (in Danish).
Dutch Ministry of Economic Affairs, 1991. PREPARE Manual for the Prevention
of Waste and Emissions. NOTA Publication. ISBN 90 346 2565 6. Leiden, The Energy Authority of New South Wales, 1985. Cost Effective Energy Use in
Meat Processing. New South Wales Government.
Filstrup, P., 1976. Handbook for the Meat By-products Industry. Alfa-Laval
Slaughterhouse By-products Department, Denmark.
Gracey, J.F. and Collins, D.S., 1992. Meat Hygiene, 9th Edition. Balliere
Tindall. London.
Hansen, P-I. E., 1994. Some Environmental Aspects of Meat and By-Products
Processing, 40th International Congress of Meat Science and Technology, The Hague, Netherlands.
Hansen, P-I. E., 1996. Introduction of cleaner technology in Danish
slaughterhouses. Fleischwirtschaft 76 (3), 277.
Hansen, P-I. E., 1997. Implementation of Cleaner Technology in Danish
Slaughterhouses. Danish Meat Research Institute.
http://www.dmri.dk/general.php3?nid=2 (accessed 9 March 2000).
Hansen, P-I. E. and B. F. Mortensen, 1992. Reduction of Pollution and
Reclamation of Packaging House Waste Products, in A.M. Pearson and T.R.
Dutson (eds), Inedible Meat By-products. Advances in Meat Research 8.
Hrudey, S.E., 1984. The management of wastewater from the meat and
poultry products industry. In Barnes et.al. (eds), Surveys in Industrial Wastewater Treatment. Food and Allied Industries. Pitman. Great Britain.
International Chamber of Commerce (ICC), 1991. ICC Guide to Effective
Environmental Auditing. ICC Publishing S.A. Paris.
Johns, M., 1993. Developments in Waste Treatment in the Meat Processing
Industry—A Review of Literature, 1979–1993. Commissioned by the Meat Research Corporation (MRC).
Jones, H.R., 1974. Pollution Control in Meat, Poultry and Seafood Processing.
Noyes Data Corporation. Park Ridge, New Jersey.
McDonald, B. (ed.), 1990. Abattoir wastewater and odour management. CSIRO
Meat Research Laboratories. Australia.
McNeil, I. and Husband, P., 1995. Water and Waste Minimisation. Optimisation
of Water Use and Control of Waste in Abattoirs. Australian Meat Technology Cleaner Production Assessment in Meat Processing
Meat and Livestock Australia (MLA), 1998. Benchmarking of Environmental
Performance. Project No. RPDA.308. Prepared by Gutteridge Haskins and Davey Pty Ltd.
Meat Industry Research Institute of New Zealand (MIRINZ), 1996. Evaluation of
Beef Paunch Contents Handling Practices. Prepared by van Oostrom, A.J. and Muirhead, R.W. MINRINZ Report No. MIRINZ 967. ISSN 0465-4390.
Meat Research Corporation (MRC), 1995. Identification of Nutrient Sources,
Reduction Opportunities and Treatment Options for Australian Abattoirs and Rendering Plants. Project No. M.445. Prepared by Rust PPK Pty Ltd and Taylor Consulting Pty Ltd.
Meat Research Corporation (MRC), 1996. Environmental, Technical and
Economic Evaluation of Stickwater Evaporation Process. Project No. M.734A.
Prepared by CMPS&F Pty Ltd.
National Productivity Council, India, 1994. From Waste to Profits: Guidelines
for Waste Minimization. National Productivity Council. New Delhi.
Ockerman, H.W. and Hansen, C.L., 2000. Animal By-Product Processing and
Utilization. Technomic Publishing Co., Inc. Lancaster, USA.
Ontario Ministry of the Environment, 1999. Guide to Resource Conservation
and Cost Saving Opportunities in the Ontario Meat and Poultry Sector. Revised edition, July, 1999. Original edition (1994) prepared by Wardrop Engineering Pearson, A.M. and Dutson, T.R. (eds), 1992. Inedible Meat By-Products.
Advances in Meat Research, Volume 8. Elsevier Applied Science. Barking, UK.
Savell, J.W. and Smith, G.C., 1998. Laboratory Manual for Meat Science. 6th
Edition. American Press. Boston, Massachusetts.
Tenorio, D.O., Esquerra, R.L. et. al., 1996. Pollution Prevention and Control
Guide for Slaughterhouse Industry. Environmental Division, Industrial Development Institute, Department of Science and Technology and Animal Products Development Center, Bureau of Animal Industry, Department of Agriculture, The Philippines.
United Nations Environment Programme (UNEP), 1991. Audit and Reduction
Manual for Industrial Emissions and Wastes. Technical Report Series No. 7.
UNEP Industry and Environment. Paris.
United Nations Environment Programme (UNEP), 1995. Cleaner Production: A
Training Resource Package. UNEP Industry and Environment. Paris.
United Nations Environment Programme (UNEP), 1996. Environmental
Management in the Brewing Industry. Technical Report Series No 33. UNEP Industry and Environment. Paris.
United Nations Environment Programme (UNEP), 1996A. Guidance Materials for
the UNIDO/UNEP National Cleaner Production Centres. UNEP Industry and Environment. Paris.
United Nations Environment Programme Cleaner Production Working Group for
the Food Industry, 1999. Cleaner Production Checklists for the Food Industry.
Internal document, available at http://www.geosp.uq.edu.au/emc/CP/ United Nations Environment Programme Industry and Environment (UNEP IE),
1995. Food processing and the environment. UNEP Industry and Environment
18(1). ISSN 0378-9993.
United Nations Environment Programme, International Chamber of Commerce
and International Federation of Consulting Engineers (UNEP/ICC/FIDIC), 1997:
Environmental Management System Training Resource Kit. ISBN92-807-1479- 1. Available from SMI Distribution Services Ltd., P.O. Box 119, Stevenage, Hertsfordshire, SG 14TP, United Kingdom.
Annex 1 References and Bibliography
United States Environment Protection Agency (US EPA), 1992. Facility
Pollution Prevention Guide. EPA/600/R-92/088. Cincinnati, Ohio.
United States Environment Protection Agency (USEPA), 1998. Waste
Minimization Opportunity Assessment Manual. Technology Transfer Series.
EPA/625/7-88/003. Cincinnati, Ohio.
Annex 2 Glossary
Best available technology and best availabletechniques (from an environmental viewpoint). BATcovers both equipment and operation practice.
Biochemical oxygen demand: a measure of thequantity of dissolved oxygen consumed by micro-organisms due to the breakdown of biodegradableconstituents in wastewater over 5 days.
Chlorofluorocarbon: CFCs have very good technicalproperties as coolants, but are causing depletion ofthe ozone layer, which protect humans, animals andcrops against ultraviolet radiation. CFCs and HCFCs(hydrogenated chlorofluorocarbon) are being phasedout according to the Montreal Protocol. CFC-11 iscommonly known as freon.
Cleaning in place: circulation of a cleaning solutionthrough or over the surface of production equipment.
Chemical oxygen demand: a measure of the quantityof dissolved oxygen consumed during chemicaloxidation of wastewater.
Cleaner Production Cleaner Production assessment Environmental management system Excessive growth of algae, reducing penetration oflight through water and consuming large amounts ofoxygen, resulting in a high risk of fish death due tolack of oxygen.
Hydrogenated chlorofluorocarbon; see CFC.
Hot standard carcass weight International Standard ISO 14001 EnvironmentalManagement Systems—specification with guidancefor use. International Organization for Standardization Live carcass weight Nitrogen oxides. Notation covers both NO2 and NO(nitrogen monoxide).
Polycyclic aromatic hydrocarbons: occur in flue gasesfrom combustion of fuel. Some PAHs arecarcinogenic.
Cleaner Production Assessment in Meat Processing
United Nations Environment Program Division ofTechnology, Industry and Economics United Nations Industrial Development Organization Volatile organic compounds; e.g. solvents with a lowboiling point.
unit for measuring pressure (1 bar = 0.987atmosphere) joule (1 W = 1 J/s) kilowatt hour (1 kW.h = 3.6 MJ) cubic metre (= 1000 L) 1 million joules (1 MJ = 0.278 kW.h) megawatt hour (1 MW.h equals 1000 kW.h) normal cubic meter Annex 3 Further Information

In English Meat International
Elsevier International Business Information
PO Box 4, 7000 BA Doetinchem
The Netherlands
Food Technology
Institute of Food Technologists
221 N. La Salle St. Ste. 300, Chicago, Il. 60601
United States of America
+1 31 27 82 84 24 +1 31 27 82 83 48 Fleischwirtschaft
Deutscher Fachverlag GmbH
D60264 Frankfurt am Main
+49 69 75 95 12 62 +49 69 75 95 12 60 UNEP DTIE
United Nations Environment Programme
Division of Technology, Industry and Economics
39–43, Quai André Citroën
F-75739 Paris Cedex 15
+33 1 44 37 14 50 +33 1 44 37 14 74 This organisation publishes a number of useful resources, including theUNEP Technical Report Series, Cleaner Production and environmentalmanagement training packages and UNEP periodicals such as UNEP In-dustry and Environment Review. It also maintains the InternationalCleaner Production Information Clearinghouse (ICPIC) database whichcontains Cleaner Production case studies (see Cleaner Production on theWeb section).
Cleaner Production Assessment in Meat Processing
UNEP Cleaner Production Working Group for the Food Industry
Environmental Management Centre
The University of Queensland
Brisbane, QLD 4072
+61 7 33 65 15 94 +61 7 33 65 60 83 The aim of the group is to promote Cleaner Production in the food indus-try. The group's activities include maintaining a network of food industryand Cleaner Production experts, maintaining a library and database ofinformation related to Cleaner Production in the food industry, deliveringworkshops and seminars and producing a newsletter.
United Nations Industrial Development Organization (UNIDO)
Vienna International Centre
P.O. Box 300
A-1400 Vienna
UNIDO provides seminars, conferences, workshops, media coverage,
demonstration projects, training and information dissemination. It also
offers support in establishing National Cleaner Production Centres. Fif-
teen such centres had been set up by October 1998, with several more
on the way.
Information manuals available from UNIDO include the UNEP/UNIDO
Audit and Reduction Manual for Industrial Emissions and Wastes
UNIDO's DESIRE kit (Demonstration in Small Industries for Reducing
Wastes). In addition, nine of the National Cleaner Production Centres
have their own country-specific manuals. UNIDO has also prepared
seven manuals specific to particular industry sub-sectors and has con-
tributed to 26 UNEP Technical Reports on specific Cleaner Production
options. All these publications can be obtained through UNIDO.
Food and Agriculture Organization of the UN (FAO)
Via delle Terme di Caracalla
00100 Rome
FAO's aim is to raise levels of nutrition and standards of living, to im-prove agricultural productivity, and to better the condition of ruralpopulations. It is active in the areas of land and water development,plant and animal production, forestry, fisheries, economic and socialpolicy, investment, nutrition, food standards and commodities and trade.
It provides regular and comprehensive statistics on world food produc-tion and also commissions projects and publication related to theenvironmental sustainability of food production.
Annex 3 Further Information
Cleaner Production on the web
UNEP International Cleaner Production Information Clearinghouse (ICPIC)
ICPIC is a Cleaner Production database containing case studies, publica-
tion abstracts, lists of expert organisations, and information on the
resources available from UNEP DTIE. It is an electronic reference tool
that is searchable by key word.
The database can be accessed via the internet at the site indicated be-
low. A CD–ROM version of the database can also be ordered through
the same website.
UNEP, Division of Technology, Industry and Economics
39–43, Quai André Citroën
F–75739 Paris Cedex 15
+33 1 44 37 14 50 +33 1 44 37 14 74 US EPA Enviro$en$e
States Environmental Protection Agency's website. It provides informa-
tion on pollution prevention, compliance and enforcement. The
information available includes pollution prevention case studies, pollution
control technologies, environmental statutes and regulations, compliance
and enforcement policies and environmental guidelines.
National Technology Transfer Centre, USA
At the National Technology Transfer Centre website you can search the
internet for Cleaner Production cases.
Wheeling Jesuit University
316 Washington Avenue
Wheeling, WV 26003
United States of America
+1 80 06 78 68 82 EnviroNET Australia
The EnviroNET Australia website contains a wide range of Cleaner Pro-
duction case studies from Australia.
Environment Australia
Environment Protection Group
40 Blackall Street
Barton ACT 2600
+61 2 62 74 17 81 +61 2 62 74 16 40 Annex 4 About UNEP DTIE
The mission of United Nations Environment Programme is to provide
leadership and encourage partnership in caring for the environment by
inspiring, informing, and enabling nations and peoples to improve their
quality of life without compromising that of future generations.
The activities of UNEP DTIE, located in Paris, focus on raising
awareness, improving the transfer of information, building capacity,
fostering technology transfer, improving understanding of the
environmental impacts of trade issues, promoting integration of
environmental considerations into economic policies, and promoting
global chemical safety. The division is composed of one centre and four
units, as described below.
The International Environmental Technology Centre (Osaka) promotes
the adoption and use of environmentally sound technologies with a
focus on the environmental management of cities and freshwater basins
in developing countries and countries with economies in transition.
The Production and Consumption Unit (Paris) fosters the development of
cleaner and safer production and consumption patterns that lead to
increased efficiency in the use of natural resources and reductions in
The Chemicals Unit (Geneva) promotes sustainable development by
catalysing global actions and building national capacities for the sound
management of chemicals and the improvement of chemical safety
worldwide, with a priority on Persistent Organic Pollutants (POPs) and
Prior Informed Consent (PIC, jointly with FAO).
The Energy and OzonAction Unit (Paris) supports the phase-out of
ozone-depleting substances in developing countries and countries with
economies in transition, and promotes good management practices and
use of energy, with a focus on atmospheric impacts. The UNEP/RISØ
Collaborating Centre on Energy and Environment supports the work of
this unit.
The Economics and Trade Unit (Geneva) promotes the use and
application of assessment and incentive tools for environmental policy
and helps improve the understanding of linkages between trade and
environment and the role of financial institutions in promoting
sustainable development.
For more information contact:
UNEP, Division of Technology, Industry and Economics
39–43, Quai André Citroën
F–75739 Paris Cedex 15
As part of its continuing review of the quality and impact of publications it supports, the United Nations EnvironmentProgramme's Division of Technology, Industry and Economics would appreciate your co-operation in completing thefollowing questionnaire. 1. Quality
Please rate the following quality aspects of the publication by ticking the appropriate box: Structure of content Rigour of analysis In general, how much of the publication is: Of technical/substantive value to you? Will be used by you? What would make the manual more useful for you? 3. Effectiveness in achieving the objective
The objective of this publication is to provide the reader with an appreciation of how Cleaner Production can be applied to the meat processing industry aswell as providing resources to help undertake a Cleaner Production assessment at a meat processing facility. In your opinion, to what extend does thisdocument fulfil this objective? Please tick one box Please state reasons for your rating: a. Please state how the publication will affect or contribute to your work, illustrating your answer with examples.
b. Please indicate, in order of importance (first, second or third), the usefulness of the publication to you: For your own information As reference material As guidelines for on-the-job application Will others read your copy of this publication? If ‘yes', how many? Did you receive this publication directly from UNEP? If ‘no', who forwarded it to you? 6. General Observations
a. Please indicate any changes in the publication that would increase its value to you.
b. Please indicate, in order of importance (first, second or third), which of the following items might increase the value of the publication to you.
Translation into your own language Specific regional information Additional technical information 7. The following data would be useful for statistical analysis
Your name (optional) Professional background UNEP would like to thank you for completing this questionnaire. Please return to:
The Director
UNEP Division of Technology, Industry and Environment
Tour Mirabeau 39-43, quai André Citroën
75739 Paris Cedex 15, France
Fax: +33 (1) 44 37 14 74

Source: http://www.cimpar.org.ar/wp-content/uploads/2010/10/Valoraci%C3%B3n-de-P+L-en-el-procesamiento-C%C3%A1rnicos.pdf

381 11-22.fm

Fluoride 2005;38(1):11–22 Research report 11 WATER FLUORIDATION AND CRIME IN AMERICA Manchester, NH, USA SUMMARY: A four-part study explores possible connections between waterfluoridation and crime in America. Part A, Media-reported crime database andfluoridation, presents an observational database of violent crimes, mostly multipleshootings, and finds an unusually high percentage of them associated with waterfluoridation, suggesting the existence of a "fluoride-related" category of crime. Alow-end threshold for the toxic effects of fluoridation of 0.3 ppm is identified, andthe term "fluoridated" is defined here as having a fluoride level of 0.3 ppm or higher.In Part B, Online crime database and fluoridation, a published database of year 2000crime data for 327 US cities over 75,000 population, representing 80 millionAmericans, was expanded to include fluoridation data for these cities. Waterfluoridation was consistently associated with high crime rates at all populationlevels. Part C, Book crime database and fluoridation, examines year 2000 crimestatistics for six major crimes in the same 327 cities according to their fluoridationstatus. Cities having natural fluoridation, or which use silicofluorides or sodiumfluoride, are shown to have substantially higher crime levels than nonfluoridatedcities. Part D, Lead related crime, quantifies the amount of crime historicallyassociated with lead intoxication, thus identifying a remainder which may beassociated with fluorides. This study presents a data-backed hypothesis about onepossible cause of crime; it is not a definitive statement about crime causality.

Microsoft word - frc 2013 cover page

2ND ANNUAL FLORIDA RESIDENCY CONFERENCE May 9-10, 2013 University of Florida College of Pharmacy Gainesville, Florida Sponsored by the FSHP Research and Education Foundation 2ND ANNUAL FLORIDA RESIDENCY CONFERENCE Welcome to the Second Annual Florida Residency Conference. We are grateful to all in attendance and we are looking forward to another great conference full of high quality resident presentations, as well as some quality time with friends and colleagues. The Florida Residency Conference Steering Committee has been busy looking ahead to not only this conference but the future of the FRC.