8 Meat Safety Management at the Abattoir As indicated in previous chapters, the major causes of food-borne disease (E. coli O157, Salmonella, Campylobacter) are undetectable by traditional post-mortem meat inspection. The recommended systematic approach to managing process hygiene and controlling undetectable hazards in foods is based on Good Manufacturing Practice (GMP), Good Hygiene Practice (GHP) and Hazard Analysis and Critical Control Points (HACCP) principles. The HACCP-based approach uses risk analysis as one of its main tools, so this chapter is closely linked to Chapter 1.7. The government is responsible for formulating a food safety policy and deriving Food Safety Objectives (FSOs) from that policy (see Chapter 10.2). FSOs are used in the design of food control systems, and they may incorporate end product criteria. Some examples are the levels of pathogens allowed in a meat product, or the level of indicator organisms allowed on carcasses. The global targets for controlling food-related hazards (FSOs) set by government should be translated by the food industry into their own performance objectives (POs); these must be achievable. The role of industry is to implement risk management systems to achieve the FSOs, and these current systems can be illustrated by the following formula: GMP refers primarily to technical aspects of the whole production process; GHP concentrates on the hygiene aspects of production. However, these terms are frequently used interchangeably; indeed, with food operations, it would be very difficult to consider hygiene as stand-alone and without actual technical context. Within abattoirs, GMP/GHP programmes relate to a range of individual stages of the operation, including transport and lairaging, stunning and sticking, skinning or scalding/dehiding, evisceration, carcass splitting, washing and refrigeration. In simple terms, GMP/GHP provides general, basic principles for hygienic production of food, including: • hygienic design, construction and operation of plants; • hygienic use of machinery, equipment and tools; • plan for maintenance, cleaning and sanitation; • staff aspects, including training, health and personal hygiene; • Standard Operating Procedures (SOPs); and • identification and traceability. HACCP is a management system for food safety assurance and is based on Risk Analysis. The management of risks through HACCP is more systematic, more organized and more documented than through GHP. HACCP plans are process- and product-specific, targeting specific hazards. They include specified and quantified controls to manage risks, and they specify methods to measure whether controls are successful. In many cases, the same control measures are used in both GHP and HACCP; the difference is in the much higher specificity and measurability of their application within HACCP. There are seven principles of HACCP: 1. Identify health hazards. 2. Identify Critical Control Points (CCPs). 3. Establish critical limits for each CCP. 4. Establish a monitoring system for each CCP. 5. Establish corrective actions if CCP is out of control. 6. Verify that the HACCP plan is working effectively. 7. Establish documentation and records. All hazards associated with each process step must be identified and enlisted. The most practical approach is first to construct a process diagram, with clearly defined individual process steps. All inputs, including raw materials at each step, must then be identified. Next, the hazards (microbial, parasitic, chemical, physical) that could occur at each step are identified. The methods by which hazards are transferred to the product are identified. Finally, any redistribution of hazards within/on the product is analysed. Subsequently, the hazards that could occur in the product at a given step need to be categorized and ranked according to the risk they present. This is done in order to apportion appropriate levels of resources to their control. A simple method to determine risk categories, as shown in Table 8.1, can be used. The judged severity of the consequences of occurrence of a given hazard is correlated with the judged associated probability of its occurrence, resulting in quantitative conversion of that relationship into the final risk category. Hazards belonging to a high-risk category – e.g. Category 4 in the described method – are critical for product safety and must be efficiently controlled through CCP (see below). Hazards belonging to lower-risk categories are not critical, so can be controlled by application of general principles, i.e. by measures within GHP. A Critical Control Point (CCP) is any point along the production process where hazards can be efficiently controlled. A decision tree is useful to clarify CCPs (Fig. 8.1). CCPs are sometimes divided into two types: CCP1s and CCP2s, where CCP1s can control the hazard fully (e.g. cooking or chilling processes at given temperatures), whilst CCP2s can only minimize the hazard, but do not afford complete control (e.g. hygiene of dressing, evisceration, etc.). In conventional slaughter and dressing processes, CCP1 controls are rare: some people even consider them as non-existent. Usually the hazards cannot be totally eliminated at the slaughterline. Within the EU, where presently carcass decontamination is not allowed, most CCPs in abattoirs are actually CCP2s; however only the use of CCP is generally accepted for use in the terminology. Table 8.1. Determining risk categories. Fig. 8.1. CCP decision tree. *If the step is not a CCP, then consider control by GHP, or at a subsequent step; redesign the process if possible. **Assign retroactive CCP if control measures are available at a previous step. For each CCP, defined and measurable critical limits must be determined, below which the hazard is controlled and the product is acceptable, and above which the hazard is not controlled and the product is unacceptable. The critical limits must be easily visualized or measured. Within abattoir operations, a common and useful critical limit states that no visible faecal contamination is allowed at a particular step (e.g. after dehiding or after evisceration). Other examples of critical limits on the slaughterline are that carcass refrigeration temperature is ≤7°C, and that the temperature of the hot water in the knife sterilizers is ≥82°C. For each CCP, monitoring parameters must be established. Monitoring is often not continuous, but must be regular and of known frequency (e.g. checking temperature in sterilizers every hour). Sometimes monitoring is based on a sampling plan, but this has to be meaningful. Clearly defined methods (e.g. visual, for absence of faecal carcass contamination) must be used to monitor the CCP by trained staff. The monitoring system must state clearly who is responsible if the CCP is found to be out of control. For each CCP, specific actions are taken when critical limits are exceeded. For example, in the case of carcass contamination, trimming, or altering its disposition, may be conducted. These actions are designed to regain rapid control of the CCP (e.g. retaining carcass on the slaughter line) and to prevent reoccurrence of the problem (e.g. replace or retrain the staff). Each HACCP plan must be validated, i.e. analysed to determine that all the controllable hazards have been identified and included in the plan. The plan is then analysed thoroughly to ensure that it is complete and capable of achieving the company’s performance objectives (POs), thus ultimately enabling achievement of the government’s FSOs. Verification is conducted using measurable parameters and by comparing defined parameters with in-house and national performance; the aim is to verify that the plan is working and that all hazards are controlled. The outcomes of the HACCP system should be at least equivalent to, but would normally exceed, those of the GHP-based system. The HACCP plan must be subjected to periodic independent review. Revalidation of the HACCP plan is necessary after any changes in production or of other aspects affecting the plan. Often, product testing is used to verify that CCPs are under control and that the plan is working (see Chapter 8.2). HACCP documentation must be thorough and include all details of the HACCP plan. All monitoring, corrective actions, verification procedures and results must be recorded. The HACCP plan must be adhered to by all staff involved. Some examples of summarized documentation are given in Boxes 8.1, 8.2 and 8.3. HACCP is proactive and preventative, the aim being to anticipate problems and prevent their occurrence. It is owned by producers and staff, so compliance and participation is stimulated and motivation is usually high. HACCP is also specific, systematic and documented. These are all qualities that contribute to the effectiveness of HACCP-based systems in achieving hygienic production processes and, hence, a safe product (food). On the other hand, HACCP is demanding on staff and time. Developing, implementing and monitoring HACCP requires a team of experts in the plant, covering a range of disciplines (e.g. slaughter personnel, engineers, veterinarians, microbiologists, chemists, management). This is achievable by large operators with a workforce having all the necessary skills, but is less achievable for small operators. Operators producing a large number of products may also experience difficulty developing/implementing a separate HACCP plan for each. However, external organizations can be contracted to assist small operators to design the HACCP plans necessary for their plant; support can also be obtained from producers’ associations. Finally, HACCP systems are designed to assure product safety, whilst the normal Quality Assurance systems operating in abattoirs are designed to reassure commercial clients about varying aspects of the product. Both programmes are necessary, but in some aspects they may have opposing goals. Box 8.1. Hazard analysis: an Example at a Selected Process Step
8.1 GHP and HACCP Principles
Introduction
GMP/GHP
HACCP
Principle 1: identify health hazards
Principle 2: identify CCPs
Principle 3: establish critical limits for each CCP
Principle 4: establish a monitoring system for each CCP
Principle 5: establish corrective actions
Principle 6: verify the HACCP plan
Principle 7: establish documentation and records
Advantages and limitations of the HACCP-based system
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