Critical limit

Critical Limit a criterion of minimum or maximum value that have to be met or can not be exceeded for each preventive measure associated with the critical control point (Donald A. Corlett 1998). Each parameter is separated by acceptability or unacceptability in order to prevent from the loss of safety of the finished product. Limits must not be exceeded to eliminate completely or reduce to minimum an acceptable level of a food safety hazard.

This applies usually to psychical, biological or chemical parameters which have to be controlled based on the principles of HACCP (Hazard Analysis Critical Control Point). Critical limits are identified after hazard analysis have been implemented and critical control points have been specified.

Definition prepared by Microbiological Criteria for foods describes the critical limit as: "a maximum and/or minimum value, to which a biological, chemical or physical parameter must be controlled at a CCP (critical control point) to prevent, eliminate or reduce to an acceptable level the occurences of a food safety hazard" (Regulation (EC) No 852/2004, 2004).

HACCP System Identification of critical limits (CLs) is one of seven HACCP principles, which were established in 29th April 2004 by European Parliament and European Council as a regulation 852/2004 on the hygiene of foodstuffs . HACCP is a preventative food safety management system and it is based on 7 general principles.

Stages in establishing critical limits

Establishing a critical limits is an integral part of preparing a PCP (preventive control plan).

1. For each Critical Control Point write a critical limit for ensuring safety of food
2. If CCPs are not identified by critical limits, it is needed to establish them in order to prevent food safety hazard. Each establishment is responsible for that kind of food safety control. It is possible to obtain assistance from HACCP experts who will help to identify critical limits
3. For future references it is advisable to keep documentations and any scientific reports from outside experts of critical limits that have been identified. This all documentation can be necessary to validate that limits are properly established

In the course of setting a critical limit it is necessary to include all government regulations, safety food models, literature searches and many industry standards. After establishing critical limits for a CCP, this processing limits can be changed to more strictly controlled process or just to keep them with normal limitations. In case of exceeding a critical limits, it is ordered to initiate a corrective actions. Operational limits are different from critical limits. They show regular processing conditions and regulations are tighter than in critical limits (J. G. Surak, S. WIlson 2007).

Example of setting a critical limit

Critical limits are specific parameters or numbers which result from visual observation, for example:

• Temperature
• Time
• pH
• Water activity
• Chlorine Level
• Humidity (Donald A. Corlett 1998)

A good example of setting a critical limit can be process of milk pasteurization. Requirements for this process are that the temperature must be higher than 161 F and it should last for minimum 15 minutes to eliminate all pathogens from milk.

Another example occures in process of cooling a cooked meat product. The temperature that is maximum for product that is cooked can not remain between 40 F and 80 F for more that 4 hours neither between 80 F and 130 F for time more than 1,5 hours. It assures recontamination and that bacteria do not exist (J. G. Surak, S. WIlson 2007).

Advantages of Critical limit

A Critical Limit is an important tool used to monitor and control safety hazards in food production. It provides numerous advantages, such as:

• Ensuring safe food production - Critical Limits set acceptable parameters for safety hazards that must be met in order to produce safe food. This helps to minimize the risk of contamination and foodborne illnesses.
• Clear guidance - Critical Limits provide clear guidance to food production staff on what is considered safe and what is not. This helps to ensure that all food produced meets the necessary safety standards.
• Cost savings - By setting acceptable parameters for safety hazards, Critical Limits can help food producers to reduce costs associated with contaminated food products and foodborne illnesses.
• Improved quality - By monitoring and controlling safety hazards, Critical Limits help to ensure that the food produced has a consistent quality and is safe for consumption.

Limitations of Critical limit

• Critical limits may not be practical in certain situations. For example, in production processes with a wide variation in parameters such as temperature, it may be difficult to set a single critical limit that will be applicable to all scenarios.
• Critical limits may not always be effective in preventing food safety hazards, as certain hazards may not be visible or detected by the limits set.
• Critical limits may be difficult to implement in certain industries, such as restaurants, where the process of preparing food is less structured and less predictable.
• Critical limits may be difficult to enforce in certain industries, such as retail stores, where there are fewer resources and personnel dedicated to food safety.
• Critical limits may be difficult to monitor and verify, as there may be a lack of resources, personnel, or technology available for the job.

Other approaches related to Critical limit

• Good Manufacturing Practices (GMPs): GMPs are standards set by the regulatory agencies for the food industry to ensure food safety. They cover all aspects of the production process from the materials used to the packaging and labeling of the finished product. GMPs also define the necessary sanitation and hygiene practices that must be followed in order to ensure the safety of the food.
• Hazard Analysis and Critical Control Point (HACCP): HACCP is a system of risk analysis and risk management used in the food industry to identify, assess, and control potential food safety hazards. HACCP involves the identification of the critical control points (CCPs) in the food production process and the establishment of critical limits that must be met in order to eliminate or reduce the risk of food safety hazards.
• Risk Assessment: Risk assessment is an important part of the food safety process. It involves the identification of food safety hazards and the assessment of the likelihood of their occurrence. Risk assessment also involves the evaluation of the potential severity of the hazard and the development of risk management strategies to reduce the risk of food safety hazards.
• Sanitation and Hygiene Practices: Sanitation and hygiene practices are essential for food safety. These include the proper handling and preparation of food, the use of protective clothing and the proper storage of food.

In summary, critical limit is one of the many preventive measures that can be implemented to ensure food safety. Other approaches related to critical limit include Good Manufacturing Practices (GMPs), Hazard Analysis and Critical Control Point (HACCP), Risk Assessment and Sanitation and Hygiene Practices. All of these approaches must be followed in order to ensure the safety of the food.

Critical limit — recommended articles

HACCP system — Seven principles of HACCP — Validation master plan — System safety — Maintenance strategy — Process validation — Accident management — Compliance test — Quality control plan

References

• Corlett A. Donald (1998), HACCP User's Manual, Springer US., 242-244.
• HACCP Principles & Application Guidelines (1997), HACCP Principles & Application Guidelines, U.S. Food and Drug Administration.
• Mortimore S., Wallace C. (2012), HACCP: A Practical Approach, Springer.
• Surak G. J., Wilson S., (2007), The Certified HACCP Auditor Handbook, ASQ Quality Press, 50-55.
• Regulation (EC) No 852/2004 of the European Parliament and of the Council of 29 April 2004 (2004), Regulation (EC) No 852/2004 of the European Parliament and of the Council of 29 April 2004.
• Taylor E. (2001), HACCP in small companies: benefit or burden?, "Food Control, 12(4)".

Author: Agata Drabik