Principle 3: Establish the Critical Limits
Critical limits are the values at critical control points (CCPs) that must be achieved to ensure the safety of food. These critical limits must be monitored at CCPs, as explained in Principle 4, and failure to consistently achieve these values must result in appropriate corrective action, as outlined in Principle 5.
Choosing critical limits
The critical limits that you choose must be suitable to ensure that the control measures that you have selected at the CCPs are adequately controlled. As such, appropriate critical limits should meet the following criteria. They should be:
- Observable: Achievement of and any subsequent changes in the critical limits during processing can be detected.
- Measurable: Achievement of the critical limits can be confirmed by measurement and any deviations quantified.
- Subject to “real time” monitoring: Any observations and measurements must be capable of being made whilst processing is in progress to allow appropriate corrective actions to be made in good time.
Critical limits may be chemical, physical or even procedural in nature depending on the type of hazard that is subject to control. Some examples include:
Chemical critical limits
- Water activity (Aw)
- Salt content
- Mycotoxin levels
- Absence of allergens
Physical critical limits
- Dried weight
- Absence of metal
- Moisture content
Procedural critical limits
- “Supply of raw beef from approved slaughterhouses which have specific controls in place to minimise the risk of contamination of meat intended to be eaten raw or lightly cooked.”
- The critical limits for controlling Salmonella in chicken pieces at the cooking step (CCP) could be 70°C for 2 minutes. Both the time and temperature are critical limits and must both be achieved.
MyHACCP tool requirements
1. What is the critical limit for this critical control point?
- “70°C for 2 minutes”
- “Aw of 0.92”
- “pH of 4.0”
2. Provide details of how the critical limit was determined
3. Is the critical limit appropriate to control the specific hazard?
4. Is the critical limit measurable or observable in real time?
5. Is there a target value?
- The critical limits for controlling Salmonella in chicken pieces at the cooking step (CCP) could be 70°C for 2 minutes. However, a target value of 72°C could be set to provide extra assurances that the minimum temperature will be consistently achieved.
Documentation and Records
A review of this principle should be scheduled and triggered if there are changes within the company or new information becomes available (e.g. legislation, emergence of a new hazard), as outlined in Principle 6.