Critical Control Points and Critical Limits
Make the limit measurable
A CCP is a step at which control can be applied and is essential to prevent, eliminate, or reduce a significant hazard to an acceptable level. The Codex decision tree is guidance, not law: answer it honestly, because applied mechanically it can create a CCP for a hazard already controlled elsewhere or push a genuine CCP into a PRP. Fewer, well-chosen CCPs beat a long list.
A critical limit (CL) is a measurable value separating acceptable from unacceptable product. It must be objective, quick to measure and linked to the hazard: 74 °C for 15 seconds, pH 4.6 or below, water activity 0.85 or below, 200 ppm free chlorine, a 2.0 mm ferrous test piece on a metal detector. Wording such as “sufficiently cooked” or “clean” fails because two trained operators could disagree.
Two concepts trip candidates. First, operating limits: a plant may set a tighter target (77 °C) to keep the process safely inside the CL (74 °C). The CL remains the absolute boundary; breaching the operating target triggers adjustment, not necessarily a deviation. Second, a CL must be validated - backed by science, challenge studies or a recognised process authority - before the plan is used.
Worked example: a continuous fryer. CL: 74 °C product core held 15 s. Operating target: 77 °C. Monitoring: continuous probe and recorder, checked hourly against a calibrated thermometer. If the recorder shows 72 °C, the CL is exceeded and the corrective-action procedure applies to all product made since the last acceptable check.