Critical limits in HACCP: how to set them correctly in food production

• Minimum cooking temperature
• Maximum cooling time
• Maximum pH level
• Maximum water activity

Why critical limits matter

• Operators do not know what to aim for
• Monitoring becomes meaningless
• Deviations are unclear
• Corrective actions become inconsistent

• Clear decision points
• Consistent production
• Reliable food safety outcomes
• Better audit performance

Common mistakes in setting critical limits

Many businesses make the same errors.

Copy-paste limits

Some teams copy limits from templates or other companies. However, processes differ. Equipment differs. Product size differs. Therefore, copied limits may not apply to your operation.

Confusing targets with limits

A target is what you aim for. A critical limit is the minimum or maximum that must not be crossed.

• Target: cook to 80°C
• Critical limit: must reach at least 75°C

Limits that are not measurable

Some limits are written as:

• “Cook thoroughly”
• “Cool quickly”

These are not limits. They are instructions. A critical limit must be measurable.

No link to hazard

A limit must relate to a specific hazard. If you cannot explain what hazard it controls, the limit is weak.

How to set critical limits correctly

To set strong limits, follow a clear structure.

Step 1: Define the hazard clearly

Do not generalise. Instead of “bacteria,” specify:

• Salmonella
• Listeria monocytogenes
• Clostridium perfringens

Clear hazards lead to clear limits.

Step 2: Identify the control measure

Ask:

• What step controls this hazard?
• Is it cooking, cooling, pH control, or something else?

This becomes your CCP.

Step 3: Define measurable parameters

Critical limits must be measurable.

• Temperature
• Time
• pH
• Water activity

Avoid vague wording.

Step 4: Use validated values

Critical limits must come from validation.

• Process validation vs verification in food production

• Scientific studies
• Regulatory guidelines
• Expert input
• In-house testing
•  

Step 5: Build in safety margin

Do not set limits at the exact failure point. Instead, create a buffer.

• If 75°C ensures safety
• Set monitoring target higher, such as 80°C

This reduces risk of deviation.

Real example from food production

Consider a central kitchen producing cooked chicken.

• Cook to 75°C

• No validation data supports this
• No probe calibration check exists
• No defined holding time

• A written limit
• A validated and verified limit

How this links to validation and verification

Critical limits sit between validation and verification.

• Validation proves the limit works
• Monitoring checks the limit is met
• Verification confirms the system works

• Scientifically justified
• Clearly defined
• Consistently monitored

What auditors look for

During an internal audit ISO 22000 or certification audit, auditors will check:

• Is the critical limit clearly defined?
• Is it measurable?
• Is it based on validation?
• Is monitoring consistent?
• Are deviations handled properly?

Business impact of poor critical limits

When limits are weak:

• Food safety risk increases
• Shelf life becomes unstable
• Product consistency drops
• Audit findings increase
• Scaling becomes difficult

• Production becomes stable
• Teams work with clarity
• Decisions are faster
• Systems scale more easily

Final advisory

Ask yourself:

• Are our critical limits based on science?
• Or are they based on habit or templates?