Evaluating Risks and Establishing Food Safety Objectives and Performance Objectives
2.1 Introduction
Societies charge public institutions and organizations with defining the “level of protection” regarding risks in daily life that should be achieved to assure the health and safety of the public. In the case of food safety, this responsibility usually resides with competent authorities that have been given this mandate by national or local legislation. Industry is responsible for assuring the safety of the products that they put onto the market or that they sell to the public. Within the context of their specific respon-sibilities, government and industry function as risk managers and share the common goal of ensuring that consumers can enjoy safe and wholesome foods.
Competent authorities may use different approaches when responding to an emerging food safety concern or when seeking to enhance current levels of food safety proactively. Their choice of actions to minimize risk to consumers depends on the circumstances and urgency of the situation. This flex-ibility is necessary because the factors surrounding concerns related to food safety vary (e.g., nature of the hazard, population affected, severity of the disease, frequency of occurrence, potential for wider dissemination of the disease agent). It is neither possible nor desirable to prescribe specific steps for control authorities to follow when responding to food safety concerns. However, some gen-eral guidelines can be given.
In addressing a food safety concern, whether wishing to reduce a current concern or to bring an increasing risk under control, risk managers must evaluate whether the situation is under sufficient control or there are sound reasons for concern. In many situations concerns are raised that, upon closer examination, are already adequately controlled by existing control measures or which do not constitute a public health issue. In the latter instance, a rapid decision must be taken to avoid wasting time and money on issues that have little impact on public health.
As new food safety concerns are recognized, some understanding of the nature and properties of the hazard, and how it leads to foodborne illness, is essential for control. Risk managers in govern-ment and industry are obliged to consider the frequency or concentration of the hazard that would be acceptable in foods and not cause illness when the food is handled and prepared as expected. Food safety managers have depended on epidemiologic studies and historical product/processing data to identify problems and determine their cause. This information then forms the basis for control options that could be applied to prevent, minimize or reduce the hazard.
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A formal process has seldom been applied to determine what a society or country would consider as an appropriate level of consumer protection in regard to a foodborne microbiological hazard. Yet, governmental risk managers have such goals in mind when developing and implementing policies and strategies for the control of microbiological hazards. There is a long history of implicitly or intuitively selecting public health protection options that provide the basis for the robust food safety manage-ment systems that currently exist.
This level of protection may not be explicitly expressed, but may be estimated from data on inci-dences of domestically occurring illnesses. Taking foodborne listeriosis as an example, the estimated prevalence reported for a number of countries ranged from 0.1 to 1.3 cases per 100,000 about a decade ago (Table 2.1). According to more recent data from Europe (EDCD 2013), the overall case rate for listeriosis was 0.33 per 100,000 in 2010, with highest rates reported by Finland (1.33 per 100,000 population), Denmark (1.12 per 100,000) and Sweden (0.67 per 100,000 population), while other Member States recorded rates below 0.6 per 100,000 population. US CDC presented compre-hensive estimates of foodborne illnesses in 2011, in which the incidence for listeriosis was estimated as 0.53 (0.19–1.06) per 100,000 (Scallan et al. 2011). Under the auspices of the World Health Organization, the Foodborne Disease Burden Epidemiology Reference Group (FERG) conducted foodborne disease burden studies since 2007. Based on systematic reviews into the literatures and meta-analysis studies, FERG reported estimates of listeriosis cases at the global level in the year 2010 to have been 23,150 (95% credible interval 6061–91,247), 5463 (1401–21,497) deaths, and 172,823 (44,079–676,465) Disability- Adjusted- Life-Years or DALYs (Maertens de Noordhout et al. 2014).
These case numbers can be converted to an estimated 2014 global incidence rate of 0.31 (0.08–1.23) per 100,000, assuming that the global population in 2014 was 7.4 billion.
Table 2.1 Reported incidence of listeriosis in selected countries
Panel Nation
Incidence estimate
(cases/100,000/year) Period Comment
Aa Australia 0.18–0.39 1991–2000
Canada 0.1–0.2 1990–1999
0.17–0.45 1987–1994
Denmark 0.48/0.64 1991/1992
0.75–0.88 1996–1998
Germany 0.34 Pre −1984
0.25 Late 1990s
France 0.68/1.30 1991/1992
0.38/0.67 1995/1996
Italy 0.35 1991/1992
Netherlands 0.13–0.19 1996–1999
New Zealand 0.4/0.61 1991/1992
Sweden 0.42 1990s
UK 0.14–0.23 1984–1996 Excludes outbreaks 1987–89
0.40–0.46 1987–1989 Includes outbreaks 1987–89
USA 0.46 1983–1992 Active reporting
0.14 1983–1992 Passive reporting
B USAb 0.53 (0.19–1.06) 2000–2008 Active surveillance; estimated US population of 299 million in 2006
Worldc 0.31 (0.08–1.23) 1990–2012 Systematic review and meta-analysis; estimated global population of 7.41 billion in 2014
aData from Ross et al. (2000)
bData from USA Scallan et al. (2011)
cData from Maertens de Noordhout et al. (2014)
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Generally, listeriosis cases are considered to be sporadic and not associated with identified out-breaks. Although foods are recognized as the primary source of listeriosis, little is known about fac-tors leading to sporadic cases or how they may be reduced. Most countries have therefore, albeit perhaps not deliberately, set protection at current levels and respond to unusual increases above the country’s baseline. This does not mean that future reductions in the incidence of listeriosis cannot be a goal of a country’s food safety enhancement program. As the factors causing sporadic cases become clearer, food safety policies can be modified to reduce the incidence of listeriosis and, thereby, achieve a higher level of protection. The availability of Whole Genome Sequencing (WGS) techniques has led to an increasing portion of sporadic cases are being redefined as geographically and temporally dif-fuse outbreaks.
Knowledge of the true level of protection in a society depends on the disease surveillance system.
Not all countries have detailed epidemiologic data describing the current situation for every food-borne pathogen; however, some level of surveillance is in place in most countries and can be put to good use to prioritize risks posed by foodborne hazards (Gkogka et al. 2011). Moreover, analysis of a particular food production system allows identification of the hazards and factors either increasing or controlling a particular risk. Ideally, integration and application of epidemiologic data from various appropriate data systems would inform the evaluation of food safety strategies to allow proper modi-fication of food safety programs and to determine equivalency in health protection between alterna-tive food safety strategies (ICMSF 2006a).
Understanding of the current level of protection and setting future goals requires evaluating public health risks associated with the concentration and/or frequency of particular hazards in foods or cat-egories of foods. This evaluation may be done in a number of different ways, depending on the issue, the scientific insights available (or key data lacking) as well as the extent that evaluation approaches can be agreed between stakeholders. In practice, the evaluation ranges from a simple qualitative esti-mation of risk to a quantitative risk assessment (see Sects. 2.4 and 2.7).
The current or future public health status relating to food safety may be expressed in terms of the level of “risk” to human health, i.e., either the current level of risk or a future level of risk. The latter case applies when governments or public health bodies set public health goals to inspire action to improve the current public health status and reduce the prevailing disease burden. Examples of such future public health goals are the Healthy People 2010 and 2020 target objectives articulated by pol-icy makers in the USA (FDA/FSIS 2001, 2010) and the target set by the UK Food Standards Agency to reduce the incidence of foodborne disease by 20% by April 2006 (FSA 2000).
The World Trade Organization’s Sanitary and Phytosanitary (SPS) Agreement (SPS) formally defined the “Appropriate Level Of (sanitary or phyto-sanitary) Protection (ALOP)” as: “the level of protection deemed appropriate by the Member (country) establishing a sanitary or phyto-sanitary measure to protect human, animal or plant life or health within its territory” (WTO/SPS 1994). Under the umbrella of WTO, the term ALOP is an expression that has legal weight and should be interpreted as referring solely to the level of protection that is currently achieved in a particular country (FAO/
WHO 2006). Although no country has formally published ALOP values, examples of “default”
ALOPs have been suggested (EFSA 2007), i.e., the incidence of Salmonella in Finland and Sweden at the time they joined the European Union as well as the use of the background level of cryptospo-ridiosis in the USA as a basis for establishing levels of treatment for drinking water. The SPS Agreement recognizes that “many members refer to this concept as the acceptable level of risk” when considering ALOP.
The Commission prefers the term “tolerable level of risk” (TLR) instead of “acceptable level of risk” (ICMSF 2002), because risks related to the consumption of food are seldom “accepted”, but at best “tolerated” in lieu of various other risk priorities to be managed by governments and of continu-ous improvement efforts of governments and industry. Reflecting on the ALOP term, the Commission feels that using the word “appropriate” could be interpreted as a target level of protection, i.e., a level
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to strive for as an endpoint, which would loose the ambition of continuous improvement underlying many public and private food safety management policies. The following phrase covers what the Commission considers the tolerable level of risk (TLR): “risk that society regards as tolerable in the context of, and in comparison with, other relevant risks in everyday life”. The TLR is established fol-lowing consideration of public health impact, technological feasibility, economic implications, etc.
Like the ALOP, the TLR can be expressed in a number of different ways, for example, the number of illnesses occurring per annum due to a certain microbial hazard per 100,000 population in a country.
A hypothetical example could be 0.5 cases of listeriosis per 100,000 population per year.
Although deciding on a TLR is a societal matter, sound scientific principles should underline the evaluation of risk and inform public health decision-makers. Although the dimensions and expres-sions of ALOP and TLR are similar, TLR is a more flexible concept as it can both relate to a current situation of public health protection being achieved in a country as well as a goal for future improve-ment in the level of protection.
Food operators cannot directly use a public health goal or level of protection to establish the condi-tions of food processing such that the necessary level of control is achieved in line with the TLR/
ALOP through measures that eliminate, prevent, or reduce microbiological hazards that may contrib-ute to the incidence of a disease. In this book and before (ICMSF 1998a, 2002), the concepts of Food Safety Objective (FSO) and Performance Objective (PO) are discussed as risk-based metrics that allow government risk managers to effectively communicate precise food safety goals to industry and trade partners. In this update of ICMSF Book 7 (ICMSF 2002), the original concept of FSO proposed by the Commission in 2002 has been aligned to that of Codex Alimentarius (CAC 2007a, 2013a), keeping to FSO for the acceptable level of a hazard at the point of consumption and using the term PO to express such levels at earlier points in the food supply chain.
FSO and PO are stated by Codex Alimentarius to signify a maximum frequency of a particular microbial hazard, a concentration or a combination of both that is considered to be tolerable for con-sumer protection in a particular food product or category of foods. In other words, at the point that they are established, these risk- based metrics make explicit to the industry what the upper level of a hazard is that can be tolerated in the food such that ultimately the risk at consumption is in line with the ALOP. As such, industry can then establish the adequate food safety management system at the point they are responsible to effectively control the hazard concerned to the tolerable level (i.e., the PO). Recent peer-reviewed literature has seen a number of studies interrelating ALOP and FSO and/
or establishing control measures on the basis of FSO/PO (Crouch et al. 2009; Membré et al. 2007;
Rieu et al. 2007; Sosa et al. 2011; Gkogka et al. 2013; Mataragas et al. 2015). While FSO and PO are newly articulated outcome targets for food safety management, verification of whether these targets are being met can be assessed using the existing food safety metrics such as microbiological criteria (MC). In association with the revised Codex guidelines on the application of MC (CAC 2013b), the Commission contributed to a working group paper in which several hypothetical studies illustrate how MC can be established to operationalize a PO or FSO (Zwietering et al. 2015).
ICMSF would propose that the concepts of FSO/PO do not only apply to pathogens, but also to their toxins or other harmful metabolites. However, the concepts do not apply to microorganisms that have no impact on the health of consumers, e.g., utility microorganisms and indicator microorgan-isms. In the following the current chapter, the concepts are discussed mostly in the context of patho-genic microorganisms, however, Chap. 14 provides an example of how these concepts can be used in the context of aflatoxins in peanuts.
Depending on the urgency of the situation, the availability of the necessary resources, the complex-ity of the hazard, and data availabilcomplex-ity and gaps, governmental and industry risk managers will need to decide on the value of setting an FSO/PO as a risk-management option, as well as on the best approach to derive values for these metrics. In principle, values for FSO/PO can be derived by advice from a few specialists, by larger expert panels, or with the aid of a quantitative risk assessment.
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The FSO/PO may be based on a realistic estimate of the risk but can also, when short of time and/or knowledge, be based on a detailed examination of the frequency and/or concentration of a hazard that is expected to keep the situation under control.
The Commission considers that the establishment of meaningful FSO or PO values for particular hazard/food combinations or intervention steps along a food supply chain will typically require quan-titative, risk-based approaches. Also, following the principle concept, the FSO should be derived from an articulated public health target, such as the ALOP or TLR. Because of their link with public health protection policies, FSOs can only be set by competent authorities. By setting an FSO, competent authorities articulate a risk-based limit that should be achieved operationally within the food supply chain, while providing flexibility for different production, manufacturing, distribution, marketing, and preparation approaches. Notably, an FSO could be derived from the performance of concurrent food safety management, articulating this performance to the industry or to trading partners in the language of a risk-based metric, where the public health policy is to maintain the risk at the “status quo” level. Authorities can also set advisory POs at particular points in the food chain to provide further guidance on risk-based limit to be achieved for those industries for which they consider it appropriate. However, it is expected that food business operators may wish to derive PO values for the point in the food supply chain that they are responsible for such that they ultimately align their food safety management systems such as to meet the FSO articulated by government (CAC 2007a).
Whereas a quantitative risk assessment compiled on the basis of a thorough analysis of public health data, including epidemiological surveys, knowledge of the impact of hazards on consumers, data on industry’s operations and ultimate exposure of consumers to particular hazards arguably pro-vides for the most comprehensive basis to establish values for FSOs (as well as for ALOP or TLR values), FSO values can also be derived from quantitative insight into the dose-response relationship between consumer exposure to different levels of a particular hazard and the consumer response in terms of illness. As noted above, such a hazard characterization relationship is best part of a risk assessment, but if such a curve is available for a given hazard and deemed appropriate to use for the population/situation at hand, it can be a helpful basis to relate the FSO to the ALOP even without developing a more complete quantitative risk assessment.
A PO can be derived from an FSO derived by a competent authority from a stated ALOP, or directly from the ALOP without explicitly articulating an FSO, on the basis of a quantitative risk assessment developed for a specific pathogen in a particular food for/by a competent authority or by an international intergovernmental organization with appropriate competencies. Food business opera-tors can derive a PO from an FSO articulated by government or on the basis of a (usually quantitative) evaluation of a hazard in the part of the food supply chain for which they are responsible. In the latter situation, the PO may not be related to FSO or ALOP values set by government, but the concept itself may still be of value for coordinating food safety management across the food supply chain. For the industry, thus, the PO is the primary means for establishing the level of control needed at a specified step in the food supply chain and for communicating this to other stakeholders in and along this food supply chain. To achieve a PO, the food business operator will have to establish a food safety manage-ment system at the step in the relevant food supply chain that essentially converts the hazard level at the start of the step to the PO level at the end of the step. The metric that relates to the required conver-sion of the hazard level is the Performance Criterion (PC) as discussed in Chap. 1. How ALOP, FSO and PO relate to PC, MC and other metrics has been agreed on at Codex level (CAC 2007a).
It may not always necessary to articulate an FSO in relation to an ALOP or TLR, for instance when a microbiological risk assessment can relate the tolerable level of risk at the population level to one or more suitable POs along a particular food supply chain. An example would be a ready-to-eat food where the levels of a pathogenic microorganism of concern remains unchanged between product manufacture and consumption. Similarly, it may not always be useful to focus on the FSO value, for example when a competent authority seeks to communicate a default or safe-haven value for the
2.1 Introduction
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maximum tolerable hazard level at a certain point in the food supply chain for regulatory enforcement in the form of a PO. Enforcement at the consumption stage through articulating an FSO and assessing compliance to it would not be practical.
It is expected that, in practice, POs rather than FSOs will most often serve the purpose of making explicit the required stringency for control of a hazard. For instance, governments may articulate a PO as their expectation of what needs to be achieved by food safety management system at a particular stage in the supply chain, especially where they have or consider having enforcement related perfor-mance metrics such as a MC. Along the food supply chain, obviously, the PO concept may be a useful metric to express what level of hazard control is to be delivered as the outcome of a step in the food supply chain, which represents an input to a subsequent step, such that the material going into the subsequent step is suitable for instance for the product and process design of the food being manufac-tured. Through the language and the concepts of FSO and PO the various food business operators that control separate steps in the food supply chain continuum can coordinate and integrate their hazard controls in order to meet an FSO/ALOP, when articulated, or to ensure that other (quantitative) bench-marks for food safety (i.e. standards, guidelines, specifications) are being met in accordance to the food product and its intended use.
There are several notable differences between the new risk-based metrics FSO/PO and the concept of the MC that was launched in the 1980s (NAS 1985; ICMSF 1986) and adopted by Codex (CAC 2013b). These differences are shown in more detail elsewhere (see Chap. 5, Table 5.1). Essentially, FSOs and POs can help to design the required stringency of the control of food operations (Zwietering et al. 2015), but are not intended for the verification of product/process control or for determination of lot acceptance, which instead rely on metrics such as MCs (CAC 2013b; Caipo et al. 2015). FSOs/
POs are also useful when comparing the safety goals of different countries or trade partners and can assist in determining equivalence of seemingly different control measures used for health protection.
Below, the concepts of FSO/PO are introduced as tools to express and communicate in practical terms the desired level of consumer protection. The following sections also provide information on some of the additional tools that have been used to characterize the public health situation.