GB/Z 23785-2009Guidelines for incorporating microbiological risk assessment in food safety risk management (English PDF)

Foreword

The guidance of technical documents proposed by the China National Institute of Standardization.

The guidance of technical documents by the National Food Safety Management Technical Standardization Technical Committee (SAC/TC313) centralized.

The main drafting of the guidance of technical documents. China National Institute of Standardization, China Agricultural University, the National Food Industry Standardization Technical Committee Council.

The main drafters of this technical guidance document. Xu Jianjun, Liu Wen, Dai Yue, Wu Guangfeng, Li Qiang, Hao Yu, Gao Sheng Pu.

Microbial risk assessment at

Guidelines for the application of food safety risk management

1 Scope

This guiding technical document provides a general framework for food safety risk management and gives guidance on applying microbiological risk assessment in food safety risk management.

This guiding technical document applies to the food safety risk management process.

2 Terms and definitions

For the purposes of this guiding technical document, the following terms and definitions apply.

2.1 hazard - a biological, chemical or physical agent in food, or a condition of food, with the potential to cause an adverse health effect.

2.2 hazard identification - the identification of biological, chemical and physical agents capable of causing adverse health effects that may be present in a particular food.

2.3 hazard characterization - the qualitative and/or quantitative evaluation of the nature of the adverse health effects associated with biological, chemical and physical agents in food.

2.4 risk - the probability of an adverse health effect caused by a hazard in food and the severity of that effect.

2.5 risk analysis - a process consisting of three components: risk assessment, risk management and risk communication.

2.6 risk assessment - a scientifically based process consisting of four steps: hazard identification, hazard characterization, exposure assessment and risk characterization.

2.7 risk management - the process of weighing policy alternatives in consultation with all interested parties, considering risk assessment and other factors relevant to consumer health protection and fair trade practices, and, if needed, selecting appropriate prevention and control options.

2.8 risk communication - the interactive exchange of information and opinions throughout the risk analysis process concerning risk, risk-related factors and risk perceptions among risk assessors, risk managers, consumers, industry, the academic community and other interested parties, including the explanation of risk assessment findings and of the basis of risk management decisions.

2.9 risk characterization - the qualitative and/or quantitative estimation, including attendant uncertainties, of the probability of occurrence and severity of known or potential adverse health effects in a given population, based on hazard identification, hazard characterization and exposure assessment.

2.10 risk profile - the description of a food safety problem and its context.

2.11 risk assessment policy - guidelines for choosing among options and for decisions in risk assessment.

2.12 risk estimate - the quantitative estimate of risk resulting from risk characterization.

2.13 appropriate level of protection (ALOP) - the level of protection of public health achieved by a food safety control system.

2.14 food safety objective (FSO) - the maximum frequency and/or concentration of a hazard in a food at the time of consumption that provides the appropriate level of protection.

2.15 performance criteria - the required outcome of a step, or combination of steps, in the food chain that ensures the FSO is met.

2.16 microbiological criteria - a definition of the acceptability of a product or lot of product, based on the presence or absence, or number, of micro-organisms (including parasites) and/or their metabolites and toxins per unit of mass, volume, area or lot.

3 General framework for food safety risk management

A general food safety risk management framework shall have four components:

- preliminary risk management activities: the initial stage of risk management, mainly the preparation of a risk profile, providing enough information for further action;

- evaluation of risk management options: weighing the possible food safety risk management options on the basis of the risk itself and other factors;

- implementation of the risk management decision: usually involving regulatory food safety measures such as HACCP;

- monitoring and review: collecting and analysing data to understand the food safety situation and the health of consumers. Where there is evidence that the established level of public health protection is not being achieved, food safety risk management options shall be selected again.

4 Preliminary risk management activities

4.1 General requirements. Preliminary risk management activities are a necessary component of the food safety risk management framework and comprise several separate parts. Figure 1 (decision chart for food safety risk management) shows the decisions taken in these activities and their relationship with microbiological risk assessment (MRA). Communication and interaction between risk managers and other parties may take place at any point of the preliminary stage.

4.2 Identification of a food safety issue. Identifying the food safety issue is the first task. Issues may be broad or specific, affect one or several commodities, involve one or several pathogens, and be existing or potential problems. They include: ranking the priority of different food safety problems, for example by risk ranking; identifying specific food safety problems of public health concern; establishing or evaluating new or alternative measures, technologies or monitoring systems; and confirming equivalence. Issues arise from many sources, such as disease surveillance, enquiries from trading partners, consumer concerns and industry needs; the risk manager decides whether each issue deserves attention.

4.3 Initiating interim measures. 4.3.1 Interim measures may be started before detailed investigation where food of unknown safety status is found (a set of plans and procedures shall be applied, or, if none exist, the risk manager shall take temporary measures immediately), where a potential problem is raised by independent researchers or the public (the risk manager takes temporary measures after seeking expert advice), and where a newly emerging pathogen causes disease (action shall be taken immediately to establish the nature and extent of the problem). 4.3.2 When interim measures are started, the risk manager needs to communicate fully with the parties concerned, collecting as much information as possible to improve the temporary measures and to replace them, when possible, with more accurate and complete measures.

4.4 Risk profile. 4.4.1 The purpose of the risk profile is to decide the next action and whether a more scientific assessment is needed. 4.4.2 The risk profile is the responsibility of the risk manager (or of a suitable person designated by the risk manager); those preparing it first determine what information is needed and how to obtain it, and identify the available resources such as staff, funds and time. It shall be concise and completed in time. 4.4.3 Its scope and detail depend on the risk and on the risk manager's need for information. 4.4.4 A risk profile includes: a brief description of the food safety issue; a general description of the hazard and of what is known about its relationship with adverse health effects; the relationship between pathogen and humans; exposure information such as routes, prevalence, hazard levels along the food chain and available controls and their feasibility; adverse effects on human health, such as type and severity, high-risk groups and prevalence and incidence data from public health surveillance; other information relevant to the decision; and recommendations to risk assessors.

4.5 Preliminary risk management decisions. 4.5.1 On the basis of the risk profile the risk manager may take a preliminary decision (see Figure 1). Where risk management is needed, relevant information may be obtained through MRA; where MRA is not needed or not possible, a limited assessment (for example exposure assessment or hazard characterization only) may be carried out. 4.5.2 As much information as possible shall be collected for the initial activities; this may lead to a new risk profile. If the risk profile shows that risk management options should be stopped, the parties concerned shall be given the reasons. Where information is insufficient to start MRA, options can only be evaluated on a limited assessment, and more detailed data shall be collected and the general framework applied again.

4.6 Defining the purpose and scope of the MRA. 4.6.1 The purpose of MRA is to give risk managers the information needed for well-founded decisions, particularly when other ways of handling information are not enough; where MRA is used to set food safety management measures, those measures shall be stated in advance. 4.6.2 The scope determines the level of detail of the information required. The exposure pathway usually covers production to consumption, and the scope shall also state the specific consumer groups of concern, the criteria for identifying adverse health effects and the factors affecting data collection, modelling, analysis and interpretation of results. 4.6.3 Before the assessment begins, the purpose and scope shall be defined through discussion among risk managers, assessors and other parties (such as food safety experts, producers and consumers), on the basis of the risk profile and other documents. Setting the risk management goals and the questions the MRA must answer is the first step.

4.7 Establishing a microbiological risk assessment policy. 4.7.1 The policy depends on the scope and purpose of the MRA and usually consists of several guidance documents, mainly on decision-making and choice of options. It covers whether other parties take part in communication, depending on the nature of the problem, resources, timetable and confidentiality, and how and when the MRA is peer reviewed. 4.7.2 Risk management agencies and other organizations shall have a general policy for conducting MRA; where data gaps exist, the policy shall be prudent and give several alternatives. The MRA shall include a risk estimate for the most sensitive population or specific subpopulations (such as children), and a multidisciplinary team shall generally be formed. 4.7.3 For a specific MRA, the risk management guidelines that affect the scope, data handling, analysis and interpretation of results shall be stated clearly and recorded. The policy for a specific problem generally includes guidelines for scientific decisions at key steps where data are highly uncertain or insufficient, the parameters reflecting health risk (such as disability-adjusted life years), and the data sources and any temporal, geographical or other limitations.

4.8 Commissioning the MRA. 4.8.1 Forming the assessment team is the risk manager's responsibility; members shall come from different disciplines. For a complex MRA a project manager may coordinate the work, turn technical content into an understandable form and report progress, and a risk communication officer may be appointed. 4.8.2 The commissioning document shall contain: a description of the specific risk management issue; the scope and purpose of the MRA; the questions it must answer; the risk profile; the type of MRA, the disciplines involved and the allocation of resources; how the risk manager will use the results; the timetable, including interim reports, meetings and final completion; criteria for judging the validity and soundness of the risk model and its conclusions; criteria for its scientific and technical adequacy; and an analysis of future data needs. The risk manager shall recognize that the expected and actual completion dates may differ.

4.9 Interaction during the MRA. Assumptions, data gaps, data selection, interpretation and modelling affect the process and the results; risk assessors shall regularly discuss these effects with the risk manager, and the risk manager shall require enough information to understand how the assessment policy affects the process and results. Peer review by experts with different views and experience shall be sought during the assessment.

4.10 Presentation of the MRA results. 4.10.1 Besides the quantitative description and risk estimate, assessors shall explain the sources of uncertainty, biological variability, data quality and assumptions; uncertainty and variability shall be described separately in the report. 4.10.2 The report shall be produced in at least two forms. The technical report, for scientists, informed managers and interested parties, shall be very detailed and include all data, references, assumptions, calculations, technical descriptions and model parameters with their values or ranges; all information on data gaps, uncertainty and variability and their effect on the results; the classification principles of any scoring or ranking system; the main factors that could change the results; the methods used to analyse bias in the risk estimate; comparisons of results obtained with and without certain data, for example model estimates against epidemiological or experimental data; and a separate discussion of the results, including the assessors' views on the feasibility and effectiveness of controls. The summary report, for risk managers and non-specialists, briefly explains the purpose, process, results and conclusions and their importance. 4.10.3 Assessors may also provide a draft report to be finalized by a team of technical writers and senior managers.

4.11 Consideration of the MRA results. On receiving the results the risk manager shall confirm that the report gives enough information for decision-making, understand how it describes the risk distribution and confirm that the questions in the commissioning document have been answered. Assessors shall tell the risk manager how the MRA was done, its particular features and limitations and their effect on the estimate, generally covering the analytical methods (such as using distributions rather than point values), the parameters used (median or mean), the effect of data gaps, uncertainty and variability, how results change with alternative data or assumptions, limiting factors, special tools such as rank correlation analysis, and a comparison with existing epidemiological data. Where tasks in the commissioning document were not completed, alternatives shall be agreed; unresolved questions shall be investigated so that they can be solved in a later MRA.

5 Evaluation of risk management options

5.1 Identification and selection of risk management options. 5.1.1 Possible options include: avoiding the risk (banning or restricting the sale of food that has been contaminated or is toxic under certain conditions); reducing exposure (advising susceptible groups not to eat certain foods); warning consumers (for example through product labels); controlling the initial level of the hazard (sterilized raw materials, rejecting materials or products that fail microbiological criteria); preventing growth of the hazard (preventing contamination along the food chain and controlling temperature, pH, water activity and preservatives); reducing the hazard level (freezing, pasteurization, irradiation); removing pathogens (washing, ultrafiltration, centrifugation); and taking no action where MRA confirms this is acceptable. 5.1.2 Evaluating options is an iterative process: the risk manager sets the desired level of public health protection, the assessors compare the impact of different control options, and evaluation continues until one or more options achieving the intended consumer protection are identified.

5.2 Steps in evaluating risk management options. After accepting the MRA results, the risk manager shall plan to consider urgent risk management measures, brief the parties concerned on the MRA, seek public comment and evaluate the options. The steps are: set up a working group to interpret the MRA and its significance for risk management; if necessary, set up working groups for specific aspects of the evaluation; once options and their effects are known, report to senior risk managers, the working group informing risk managers of the options and of public comment only when authorized; interact with the public through meetings, technical forums, formal notices and written or electronic communication, the parties including public health and medical authorities, primary producers, processors, catering, distribution, wholesalers and retailers, trade associations, consumer organizations, academic advisory committees and other authoritative bodies; senior risk managers decide the final option and inform the parties.

5.3 Application of MRA in evaluating options. Where the risk manager does not know the extent of a risk from a pathogen and the foods involved, MRA can estimate the risk and show how a producer or process causes it. The risk manager may also define the ALOP as an expected reduction of risk over a period and use MRA to evaluate options that achieve it. Where the risk is hard to establish qualitatively or quantitatively, risk characterization helps to understand its nature, and model simulations allow different ways of reducing risk to be compared.

5.4 Expressing and establishing the ALOP. The ALOP is generally expressed in relation to a disease associated with a particular hazard/food combination and its consumption. It is usually set at the level achieved by one or more existing risk management measures; being based on existing technology, the public health goal is met as long as most enterprises follow the technical requirements.

5.5 Establishing a food safety objective (FSO). 5.5.1 Combining the dose-response curve with the exposure distribution establishes a quantitative relationship between FSO and ALOP; because of the inherent uncertainty of MRA, a lower FSO value should be used to ensure the intended consumer protection. 5.5.2 Where the risk assessment and risk characterization are not yet complete, an FSO can be set indirectly by setting microbiological standards for the food.

5.6 Communication on the evaluation of options. The risk manager shall be ready to hear and consider the views of the parties, and explain the strategic plan and the reasons for the decision; assumptions, conclusions and their interpretation shall be published and archived. When drafting or revising the ALOP and/or FSO, the questions discussed include how far they improve public health, the relationship between ALOP and FSO, how they fit into overall food safety planning, and whether foreseeable changes are expected. The risk manager shall explain the effect of the selected measures on each sector of the food industry and on international trade, particularly where requirements are stricter than Codex Alimentarius, publish an implementation timetable with the decision and explain how interactive communication will take place during implementation.

6 Implementation of risk management measures

6.1 Application of the FSO. 6.1.1 Where an FSO has been established, the competent authority shall decide how it fits into the national legal and standards framework: as a food safety control measure in itself, or as a reference parameter for standards, guidelines and related documents. 6.1.2 Performance criteria may be set by the competent authority and/or industry; whoever sets them, meeting them is the responsibility of industry, and the parties shall be notified of changes. Initial hazard levels and changes during production, distribution, storage, preparation and consumption shall be considered, and exposure pathway models from MRA help in this. 6.1.3 One or more performance criteria may be applied as food safety measures in control systems based on GHP and/or HACCP, at any point of the food chain, achieving at least the hazard control level equivalent to the critical control points. If the hazard level at consumption exceeds the FSO, control measures shall be revised and/or new performance criteria introduced. Where the food does not support microbial growth, the performance criterion may be set after processing and is equivalent to the FSO; otherwise it shall be stricter. Where the food is cooked before eating and cooking reduces the hazard to the FSO, the criterion may be less strict. 6.1.4 Microbiological criteria based on the FSO help to achieve the ALOP; they may be proposed by the competent authority or trade organizations, the point of the food chain where they apply shall be determined, and they shall specify the micro-organisms to be tested, sampling, analytical methods and limits.

6.2 Application of MRA in implementation. 6.2.1 Where a common pathogen occurs in many foods, MRA can predict the relative risk of each hazard/food combination and identify which foods need stricter measures. 6.2.2 Exposure assessment helps to understand hazard control at specific points of the food chain and so to demonstrate the equivalence of alternative food safety measures.

7 Monitoring and review

7.1 Monitoring. 7.1.1 Monitoring provides information on the risk a specific hazard poses to people, to guide the choice of options and the management and evaluation of risk management actions. Food contaminant monitoring and foodborne disease surveillance data are important sources of information for MRA, for risk characterization and for building and validating models. 7.1.2 Monitoring activities include building foodborne disease databases, systematic investigation of outbreaks and integrating foodborne disease data with hazard data in food.

7.2 Review. 7.2.1 Review covers the whole risk management programme or parts of it, assessing whether its goals have been achieved and consumer protection strengthened. 7.2.2 The risk manager independently checks whether the food safety problem, or part of it, has been properly handled; the results shall be published and communicated to the parties. Further actions may include collecting additional targeted information, setting new risk reduction goals and applying other food safety measures. Decisions shall be reviewed when new information appears, comparing it with the information previously used to understand its possible effect on the MRA or on a measure.

7.3 Application of MRA in monitoring and review. Hazard characterization reflects the extent of adverse health effects from a specific hazard/food combination. MRA can predict changes in the risk of potential hazards and help design monitoring programmes to verify the predictions; it can explain significant changes in monitored foodborne disease, which may come from differences in laboratory methods, improved reporting or greater awareness; and it can check whether monitoring data are representative. Where predictions and monitoring data disagree, further scientific study is needed. Feeding new data into the model helps the review of risk management decisions.