ISO 22000 clause 8.5.4.2: justify critical limits and OPRP action criteria

What clause 8.5.4.2 requires in practice

Every CCP needs a critical limit and every OPRP needs an action criterion, and the organisation records the rationale for each one as documented information. Critical limits must be measurable, and staying within them has to ensure that the acceptable level of the hazard is not exceeded. Action criteria for OPRPs must be measurable or observable, and achieving them helps give the organisation confidence that the acceptable level of the hazard stays unbreached in practice. The difference in wording is deliberate: a CCP is the stronger, more directly decisive control and a measurable limit gives a firm basis for deciding whether product is acceptable. An OPRP may rely on a criterion that a trained person can observe, provided it is clear enough to be applied consistently.

Connect the criterion with the hazard outcome

The acceptable level identified in hazard analysis concerns the hazard in the end product. A critical limit or action criterion concerns the selected control measure. Explain how the latter supports the former through the relevant technical and validation basis.

For a CCP, conformity with the critical limit must ensure that the acceptable level is not exceeded. For an OPRP, conformity with the action criterion contributes to assurance that it is not exceeded. Do not erase this distinction by using the same vague wording for both.

Keep the relevant conditions visible. A criterion supported for one product, equipment arrangement or process may not transfer unchanged to another. Examine applicability before copying a value from external guidance or another site.

Make the decision measurable or observable

A measurable limit needs an appropriate measurement and interpretation. Specify the relevant parameter and unit or other necessary context so the operator and evaluator reach the same conclusion. The monitoring and measuring controls support confidence in the result.

An observable OPRP criterion needs sufficient definition to avoid arbitrary judgment. Where monitoring uses subjective observation, the related monitoring requirement calls for supporting instructions or specifications. An instruction such as looks acceptable is weak without an agreed meaning.

Do not confuse a desired operating target with the actual critical limit or action criterion. An organisation may choose an operating target for management purposes, but the relationship and response must be clear and technically justified.

Maintain the rationale and control changes

Document why the limit or criterion was selected, including the relevant evidence and conditions. The record should allow a competent reviewer to follow the reasoning. A number entered in a plan without its basis is difficult to defend or update.

If a proposed change affects the validated control arrangement, evaluate it before implementation and address the relevant validation requirement. Convenience in production is not an adequate reason to relax a criterion.

Why clause 8.5.4.2 matters to the business

Limits and criteria are what turn a technical decision into a daily judgement. If they are vague, two operators reach different conclusions about the same product, and the business cannot show what it relied on when a problem occurs. If they are copied from elsewhere without a rationale, they may be too lax to protect consumers or too strict to be practical. A recorded rationale also helps when change is proposed, because the people making the change can see what the original setting was meant to achieve. That reduces the temptation to relax a limit for convenience.

How to implement clause 8.5.4.2

Work backwards from the acceptable outcome to the condition that will be watched, and write the reason down. Make each rationale short and checkable, so that a reviewer can see in a minute which evidence supports the value and what would need to change if the product did.

1. Take the validated control and identify the parameter or observation that shows whether it is operating as intended.
2. For a CCP, define a measurable limit with its unit and the point at which the limit applies.
3. For an OPRP, define a measurable or observable criterion, and add a description or example images where judgement is involved.
4. Record why this limit or criterion was chosen, citing the validation evidence and the conditions it covers.
5. Keep any operating target that sits inside the limit clearly separate, so staff know which one triggers action.
6. Test understanding by asking two people to apply the criterion to the same situation.
7. Re-examine the rationale before changing a limit, product format or equipment.

Illustrative food-processing example

Illustrative allergen-control example

A manufacturer has justified an OPRP associated with an allergen changeover arrangement. Where part of monitoring is observational, it defines the relevant condition and supporting instructions so trained personnel can make a consistent judgment.

The observation does not substitute for the technical evidence needed to validate the overall control. The team keeps the capability question separate from the routine criterion used in operation.

Evidence and common mistakes