2 Microbiological risk assessment in food processing applied only to the extent required to protect human health based on scientific principles not maintained without scientific evidence based on an assessment of the risk to health that is appropriate to the The WTo turned for guidance on defining suitable criteria to the Codex Committee on Food Hygiene of the Codex Alimentarius Commission( CAC), the body set up by the WTO and the Food and Agriculture Organisation(FAO)of the United Nations to develop benchmark standards and procedures for international food safety management. The CAC subsequently developed principles and guidelines to define the nature of, and provide a methodology for, assessing the risks to human health from pathogens in foods(Anon, 1996; Anon, 1999). These guidelines provide the foundation for a common methodology for microbiological risk assessment and management by WTO countries The CAC defines microbiological risk assessment as a scientifically-based process involving four key steps which are designed to produce a risk estimate hazard identification 2. hazard characterisation 3. exposure assessment 4. risk characterisation Hazard identification identifies the causal relationship between a pathogenic agent, an illness and a food as one vector of a specified illness. Hazard characterisation, or dose-response characterisation as this stage is also known, attempts to relate the probability and severity of illness to the dose of pathogen(or toxin) ingested by the consumer. Exposure assessment seeks to estimate the scale of exposure by assessing how much and how often consumers are exposed to a hazardous agent in food as a result of contamination levels and the effects of processing, distribution and consumer use. Finally, risk characterisation synthesises the output of the previous stages to provide an estimate(qualitative or quantitative) of the level of risk for a defined group of consumers from the identified pathogen in a particular food product. This introduction shows that microbiological risk assessment is still a latively new and emerging discipline. Relatively few formal microbiological risk assessments have been completed, in part because of the resources required and the relative paucity of information in some areas. In particular, few formal assessments have been undertaken by the food industry to form the basis for risk management decisions. As a result, much remains to be discovered in the light of practical experience(some of these completed assessments are discussed Chapter 7). A number of immediate challenges have been identified by ndividual formal assessments. These challenges include(Anon, 2000a and b Ross and McMeekin, 2002) problems in the quantity and quality of suitable and relevant data issues in the handling of variability and uncertainty
• applied only to the extent required to protect human health • based on scientific principles • not maintained without scientific evidence • based on an assessment of the risk to health that is appropriate to the circumstance The WTO turned for guidance on defining suitable criteria to the Codex Committee on Food Hygiene of the Codex Alimentarius Commission (CAC), the body set up by the WTO and the Food and Agriculture Organisation (FAO) of the United Nations to develop benchmark standards and procedures for international food safety management. The CAC subsequently developed principles and guidelines to define the nature of, and provide a methodology for, assessing the risks to human health from pathogens in foods (Anon., 1996; Anon., 1999). These guidelines provide the foundation for a common methodology for microbiological risk assessment and management by WTO countries. The CAC defines microbiological risk assessment as a scientifically-based process involving four key steps which are designed to produce a risk estimate: 1. hazard identification 2. hazard characterisation 3. exposure assessment 4. risk characterisation Hazard identification identifies the causal relationship between a pathogenic agent, an illness and a food as one vector of a specified illness. Hazard characterisation, or dose-response characterisation as this stage is also known, attempts to relate the probability and severity of illness to the dose of the pathogen (or toxin) ingested by the consumer. Exposure assessment seeks to estimate the scale of exposure by assessing how much and how often consumers are exposed to a hazardous agent in food as a result of contamination levels and the effects of processing, distribution and consumer use. Finally, risk characterisation synthesises the output of the previous stages to provide an estimate (qualitative or quantitative) of the level of risk for a defined group of consumers from the identified pathogen in a particular food product. This introduction shows that microbiological risk assessment is still a relatively new and emerging discipline. Relatively few formal microbiological risk assessments have been completed, in part because of the resources required and the relative paucity of information in some areas. In particular, few formal assessments have been undertaken by the food industry to form the basis for risk management decisions. As a result, much remains to be discovered in the light of practical experience (some of these completed assessments are discussed in Chapter 7). A number of immediate challenges have been identified by individual formal assessments. These challenges include (Anon., 2000a and b: Ross and McMeekin, 2002): • problems in the quantity and quality of suitable and relevant data • issues in the handling of variability and uncertainty 2 Microbiological risk assessment in food processing
the limited availability of trained personnel debates over methodology, for example how best to model the inputs of the hazard to the supply chain and the resulting outputs with the product, and how to model dose-response data how to express the output of a risk assessment in a way that is both accurate and meaningful to food safety managers and consumers This book is the first comprehensive review not only of the methodology of microbiological risk assessment in the light of experience, but also of the range of problems encountered in practice and how these might be addressed. Two initial chapters set the scene. The first( Chapter 2) puts microbiological risk assessment in the context of the broader development of international food safety standards, whilst Chapter 3 introduces basic microbiological risk assess- ment methodology. These chapters are followed by authoritative coverage of the four key stages in microbiological risk assessment( Chapters 4 to 7), explainin and reviewing the individual steps which underpin each stage, the problems involved in a practical study and how they might be overcome or, their effects at qualitative, quantitative and computational tools(such as predictive modello least, minimised. A subsequent chapter( Chapter 10) reviews the range available to support each of these stages in an assessment. he Cac has placed risk assessment as the first step within a broader framework of risk analysis consisting of · risk assessment risk communication As its name suggests, risk assessment provides a formal, validated and transparent estimate of the level of risk which can be communicated to key groups, such as policy and decision makers, QA professionals and consumers Such assessments provide a basis for making decisions, setting priorities and adopting appropriate procedures for food safety management. The book therefore includes a chapter on the challenge of risk communication( Chapter 8). There is also a detailed introduction to the issues involved in using risk assessment as a basis for the effective management of pathogen risks related to food production( Chapter 9). Chapter 1l discusses how such assessments can be used to establish microbiological criteria( for specifications)and food safety objectives(FSOs). The chapter shows how these can be used as inputs into food safety management tools such as hazard analysis and critical control point HACCP)systems, or as benchmarks for establishing equivalence between food safety management or regulatory regimes. Chapter 12 considers in detail the critical relationship between microbiological risk assessment and food safety management systems such as HACCP systems. The concluding chapter looks at the future of microbiological risk assessment, including developments in methodology, risk communication and management, and the acceptance of ris
• the limited availability of trained personnel • debates over methodology, for example how best to model the inputs of the hazard to the supply chain and the resulting outputs with the product, and how to model dose-response data • how to express the output of a risk assessment in a way that is both accurate and meaningful to food safety managers and consumers This book is the first comprehensive review not only of the methodology of microbiological risk assessment in the light of experience, but also of the range of problems encountered in practice and how these might be addressed. Two initial chapters set the scene. The first (Chapter 2) puts microbiological risk assessment in the context of the broader development of international food safety standards, whilst Chapter 3 introduces basic microbiological risk assessment methodology. These chapters are followed by authoritative coverage of the four key stages in microbiological risk assessment (Chapters 4 to 7), explaining and reviewing the individual steps which underpin each stage, the problems involved in a practical study and how they might be overcome or, their effects at least, minimised. A subsequent chapter (Chapter 10) reviews the range of qualitative, quantitative and computational tools (such as predictive modelling) available to support each of these stages in an assessment. The CAC has placed risk assessment as the first step within a broader framework of risk analysis consisting of: • risk assessment • risk communication • risk management As its name suggests, risk assessment provides a formal, validated and transparent estimate of the level of risk which can be communicated to key groups, such as policy and decision makers, QA professionals and consumers. Such assessments provide a basis for making decisions, setting priorities and adopting appropriate procedures for food safety management. The book therefore includes a chapter on the challenge of risk communication (Chapter 8). There is also a detailed introduction to the issues involved in using risk assessment as a basis for the effective management of pathogen risks related to food production (Chapter 9). Chapter 11 discusses how such assessments can be used to establish microbiological criteria (for specifications) and food safety objectives (FSOs). The chapter shows how these can be used as inputs into food safety management tools such as hazard analysis and critical control point (HACCP) systems, or as benchmarks for establishing equivalence between food safety management or regulatory regimes. Chapter 12 considers in detail the critical relationship between microbiological risk assessment and food safety management systems such as HACCP systems. The concluding chapter looks at the future of microbiological risk assessment, including developments in methodology, risk communication and management, and the acceptance of risk by consumers. Introduction 3
4 Microbiological risk assessment in food processing 1.1 References ANON.(1995a) Results of the Uruguay round of the multilateral trade negotiations 1993: agreement on application of sanitary and phytosanitary easures World Trade Organisation, Geneva ANON.(1995b) Results of the Uruguay round of the multilateral trade negotiations 1993: agreement on technical barriers to trade. World Trade Organisation, Geneva ANON.(1996) Principles and guidelines for the application of microbiological risk assessment. Alinorm 96/10 Codex Alimentarius Commission. Rome ANON (1999)Principles and guidelines for the conduct of microbiological risk assessment. Alinorm 99/13A Codex Alimentarius Commission Rome ANON (2000a) Guidelines on hazard characterisation for pathogens in food and water(preliminary document ). World Health Organisation/Food and Agriculture Organisation of the United Nations, Ro ANON(2000b)Report of the joint FAO/WHO pert consultation on risk assessment of microbiological hazards in foods: 17-2lst July, 2000 World Health Organisation/Food and Agriculture Organisation of the United Nations. Rome BENFORD, D(2001) Principles of risk assessment of food and drinking water related to human health. Intermational Life Sciences Institute (LSD Brussels MORGAN MG(1993) Risk analysis and management, Scientific American 269 (1):32-41 PENNINGTON T H(1997) The Pennington Group Report on the circumstances leading to the 1996 outbreak of infection with E coli 0157 in Central Scotland, the implications for food safety and the lessons to be learned The Stationery Office, Edinburgh ROSS T and MCMEEKin T (2002)Risk assessment and pathogen management, in Blackburn, c de w and McClure, P(eds), Foodborne pathogens: hazards risk analysis and control. Woodhead Publishing Ltd, Cambridge TENNANT, DR(1997)Integrated food chemical risk analysis, in Tennant, DR (ed). Food chemical risk analysis. Blackie Academic and Professional TUTTLE J, GOMEZ T, DOYLE M, WELLS J, ZHAO T, TAUXE R and GRIFFIN P(1999) Lessons from a large outbreak of E coli 0157 infections Epidemiol Infect 122:195-92
1.1 References ANON. (1995a) Results of the Uruguay round of the multilateral trade negotiations 1993: agreement on application of sanitary and phytosanitary measures. World Trade Organisation, Geneva. ANON. (1995b) Results of the Uruguay round of the multilateral trade negotiations 1993: agreement on technical barriers to trade. World Trade Organisation, Geneva. ANON. (1996) Principles and guidelines for the application of microbiological risk assessment. Alinorm 96/10 Codex Alimentarius Commission, Rome. ANON. (1999) Principles and guidelines for the conduct of microbiological risk assessment. Alinorm 99/13A Codex Alimentarius Commission, Rome. ANON. (2000a) Guidelines on hazard characterisation for pathogens in food and water (preliminary document). World Health Organisation/Food and Agriculture Organisation of the United Nations, Rome. ANON. (2000b) Report of the joint FAO/WHO expert consultation on risk assessment of microbiological hazards in foods: 17–21st July, 2000. World Health Organisation/Food and Agriculture Organisation of the United Nations, Rome. BENFORD, D (2001) Principles of risk assessment of food and drinking water related to human health. International Life Sciences Institute (ILSI), Brussels. MORGAN M G (1993) Risk analysis and management, Scientific American 269 (1): 32–41. PENNINGTON T H (1997) The Pennington Group Report on the circumstances leading to the 1996 outbreak of infection with E.coli 0157 in Central Scotland, the implications for food safety and the lessons to be learned. The Stationery Office, Edinburgh. ROSS T and MCMEEKIN T (2002) Risk assessment and pathogen management, in Blackburn, C de W and McClure, P (eds), Foodborne pathogens: hazards, risk analysis and control. Woodhead Publishing Ltd, Cambridge. TENNANT, D R (1997) Integrated food chemical risk analysis, in Tennant, D R (ed), Food chemical risk analysis. Blackie Academic and Professional, London. TUTTLE J, GOMEZ T, DOYLE M, WELLS J, ZHAO T, TAUXE R and GRIFFIN P (1999) Lessons from a large outbreak of E.coli 0157 infections Epidemiol Infect 122: 195–92. 4 Microbiological risk assessment in food processing
The evolution of microbiological risk assessment S Notermans and A w. Barendsz, TNO Nutrition and Food Research Institute Zeist and f Rombouts, wageningen Universiteit 2.1 ntroduction better means of ensuring the production of safe food. As stated in Chapter 1 MRA comprises four successive key steps: (1) hazard identification, (ii) hazard characterisation, (iii) exposure assessment and (iv)risk characteris- tion. The use of risk assessment ensures that control of food safety is based on a logical and scientific approach to the problems involved. In practice elements of Mra have been utilised for many years, although, in earlier times, they were not formally recognised as such. Hazard identification, for example, began at the end of the nineteenth century when the work of van Ermengen served to clarify the etiology of botulism in humans (Van Ermengem, 1896). Later milestones in this category included the recognition of Clostridium perfringens as a foodborne pathogen in 1943 (McClane, 1979) and Bacillus cereus in the 1950s( Granum, 1997). Human infections with Listeria monocytogenes were well known by the 1940s and foodborne ansmission was suspected(rocourt and Cossart, 1997), but it was not until the occurrence of an out break in Canada in 1981 that conclusive evidence was obtained. In this case, illness followed the consumption of contaminated coleslaw (Farber and Peterkin, 2000). Since then, numerous foodborne outbreaks have been reported in different countries, and prevention of listeriosis has become a major challenge for the food industry. Regarding hazard characterisation, data have been obtained from the analysis of many incidents of foodborne disease. Although such information is not sufficient to establish dose-response relationships, some outbreaks have yielded useful data on attack rates and exposure levels for particular pathoger
2.1 Introduction Microbial risk assessment (MRA) is a relatively new tool in the quest for a better means of ensuring the production of safe food. As stated in Chapter 1, MRA comprises four successive key steps: (i) hazard identification, (ii) hazard characterisation, (iii) exposure assessment and (iv) risk characterisation. The use of risk assessment ensures that control of food safety is based on a logical and scientific approach to the problems involved. In practice, elements of MRA have been utilised for many years, although, in earlier times, they were not formally recognised as such. Hazard identification, for example, began at the end of the nineteenth century when the work of van Ermengen served to clarify the etiology of botulism in humans (Van Ermengem, 1896). Later milestones in this category included the recognition of Clostridium perfringens as a foodborne pathogen in 1943 (McClane, 1979) and Bacillus cereus in the 1950s (Granum, 1997). Human infections with Listeria monocytogenes were well known by the 1940s and foodborne transmission was suspected (Rocourt and Cossart, 1997), but it was not until the occurrence of an outbreak in Canada in 1981 that conclusive evidence was obtained. In this case, illness followed the consumption of contaminated coleslaw (Farber and Peterkin, 2000). Since then, numerous foodborne outbreaks have been reported in different countries, and prevention of listeriosis has become a major challenge for the food industry. Regarding hazard characterisation, data have been obtained from the analysis of many incidents of foodborne disease. Although such information is not sufficient to establish dose–response relationships, some outbreaks have yielded useful data on attack rates and exposure levels for particular pathogens. 2 The evolution of microbiological risk assessment S. Notermans and A.W. Barendsz, TNO Nutrition and Food Research Institute, Zeist and F. Rombouts, Wageningen Universiteit
6 Microbiological risk assessment in food processing Even in the distant past, there was evidence of a rational approach to the control of food safety. Therefore, the evaluation of MRa in this chapter begins with some historical aspects of safe food production, followed by discussion of food control systems that have been developed and applied in the past, with special reference to MRA principles. Section 2. 4 deals with the establishment of international food safety standards based on the use of risk assessment. In Section 2.5, consideration is given to the ways in which MRA is becoming integrated in food industry practices and some examples of beneficial applications are included. Finally, current issues in MRA are discussed 2.2 Historical aspects of safe food production The need to produce safe food has a long history. Problems with foodborne diseases must have been a continuous preoccupation of early humans once they began their hunting and food-gathering activities, and domestic production of food animals and crops. Although the exact timing is uncertain, organised food production probably started between 18 300 and 17000 years ago, when barley production is said to have flourished in the Egyptian Nile valley (Wendorf et al, 1979). During that time, there was a need to preserve the grain and keeping it in a dry condition was an obvious precaution. Attempts to preserve other foods were based mainly on experience gained in associating the spoilage of a food with the manner in which it had been prepared and stored. The same would be true for keeping food safe. Increasingly, it became clear that a safe condition could only be maintained if the product was kept dry and away from contact with air. Some foods were treated with honey and later with olive oil (Toussaint Samat, 1992). This led to the development of additional preservative measures such as heating and salting. Once salt had been found to have a preservative capability, its value increased, since it was not available in sufficient quantity to meet the demand. According to Toussaint-Samat(1992), the large amount of salt in the Dead Sea was one of the reasons for the interest of the romans in Palestine Over many millennia, humans have learned how to select edible plant and animal species, and how to produce, harvest and prepare them for food purposes This was mostly done on the basis of trial and error and from long experience Many of the lessons learned, especially those relating to adverse effects on human health, are reflected in various religious taboos, which include a ban eating specific items, such as pork, in the Jewish and Muslim religions Tannahill, 1973). Other taboos showed a more general appreciation of food hygiene. In India, for example, religious laws prohibited the consumption of certainunclean'foods, such as meat cut with a sword, or sniffed by a dog or cat, and meat obtained from carnivorous animals(Tannahill, 1973). Most of these od safety requirements were established thousands of years ago when religious laws were likely to have been the only ones in existence. The introduction of control measures in civil law came much later
Even in the distant past, there was evidence of a rational approach to the control of food safety. Therefore, the evaluation of MRA in this chapter begins with some historical aspects of safe food production, followed by discussion of food control systems that have been developed and applied in the past, with special reference to MRA principles. Section 2.4 deals with the establishment of international food safety standards based on the use of risk assessment. In Section 2.5, consideration is given to the ways in which MRA is becoming integrated in food industry practices and some examples of beneficial applications are included. Finally, current issues in MRA are discussed. 2.2 Historical aspects of safe food production The need to produce safe food has a long history. Problems with foodborne diseases must have been a continuous preoccupation of early humans once they began their hunting and food-gathering activities, and domestic production of food animals and crops. Although the exact timing is uncertain, organised food production probably started between 18 300 and 17 000 years ago, when barley production is said to have flourished in the Egyptian Nile Valley (Wendorf et al., 1979). During that time, there was a need to preserve the grain and keeping it in a dry condition was an obvious precaution. Attempts to preserve other foods were based mainly on experience gained in associating the spoilage of a food with the manner in which it had been prepared and stored. The same would be true for keeping food safe. Increasingly, it became clear that a safe condition could only be maintained if the product was kept dry and away from contact with air. Some foods were treated with honey and later with olive oil (ToussaintSamat, 1992). This led to the development of additional preservative measures, such as heating and salting. Once salt had been found to have a preservative capability, its value increased, since it was not available in sufficient quantity to meet the demand. According to Toussaint-Samat (1992), the large amount of salt in the Dead Sea was one of the reasons for the interest of the Romans in Palestine. Over many millennia, humans have learned how to select edible plant and animal species, and how to produce, harvest and prepare them for food purposes. This was mostly done on the basis of trial and error and from long experience. Many of the lessons learned, especially those relating to adverse effects on human health, are reflected in various religious taboos, which include a ban on eating specific items, such as pork, in the Jewish and Muslim religions (Tannahill, 1973). Other taboos showed a more general appreciation of food hygiene. In India, for example, religious laws prohibited the consumption of certain ‘unclean’ foods, such as meat cut with a sword, or sniffed by a dog or cat, and meat obtained from carnivorous animals (Tannahill, 1973). Most of these food safety requirements were established thousands of years ago when religious laws were likely to have been the only ones in existence. The introduction of control measures in civil law came much later. 6 Microbiological risk assessment in food processing