CCPs and decision trees

A critical control point is a step at which a control measure, or several control measures, essential to control a significant hazard, is applied. Two things follow from this. CCPs exist only for significant hazards. And they sit at steps where control is essential and where a failure could produce potentially unsafe food.

Not every step or check is a CCP. A plan with too many CCPs spreads attention thinly. There is no correct number. A process can have more than one CCP for the same hazard, and one CCP can control several hazards.

Some businesses find no CCPs at all. UK law accepts that this can happen in certain businesses. Codex says that if a business decides no CCPs are needed, it should review that decision periodically.

A decision tree helps you decide. It is a set of questions, asked in order, at each step where a significant hazard has been identified. Annex IV of the Codex text gives this example.

Question 1: can the significant hazard be controlled to an acceptable level at this step by prerequisite programmes such as GHPs? If yes, this step is not a CCP. If no, go to question 2.

Question 2: do specific control measures for this hazard exist at this step? If no, this step is not a CCP, and you should look at later steps. If yes, go to question 3.

Question 3: will a later step prevent or eliminate the hazard, or reduce it to an acceptable level? If yes, that later step should be the CCP. If no, go to question 4.

Question 4: can this step specifically prevent or eliminate the hazard, or reduce it to an acceptable level? If yes, this step is a CCP. If no, modify the step, the process or the product, then carry out the hazard analysis again.

You may see older trees with different questions. Use the one in your own procedures. Codex says a decision tree should be used flexibly, and that other approaches, such as a worksheet or expert advice, are acceptable.

Here is a worked example with raw chicken in a restaurant. The significant hazards are Campylobacter and Salmonella. Start at delivery. Question 1: can prerequisites control the hazard to an acceptable level? No, because a good supplier cannot remove it. Question 2: is there a specific control at this step? No, nothing at delivery kills the bacteria. So delivery is not a CCP, and you move on.

Now look at cooking. Question 1: no. Question 2: yes, there is heat. Question 3: will a later step deal with the hazard? No. Question 4: can this step reduce it to an acceptable level? Yes. So cooking is a CCP.

Sometimes two steps work together. When a large pot of rice is cooked, the heat kills active bacteria, but spores of Bacillus cereus survive. Cooling then stops the spores from germinating and growing. So cooking may be a CCP for one part of the hazard, and cooling may be a CCP for the other. When control measures at two steps combine to control the same hazard, both steps are treated as CCPs.

Not every significant hazard ends in a CCP. In a sandwich bar, bacteria from hands could reach ready-to-eat fillings. Question 1: can prerequisites control this to an acceptable level? Yes, through handwashing, clean equipment and separation. So this step is not a CCP, and the control stays a GHP. It is still important, and it may need greater attention.

Allergens can be controlled at a CCP too. In a factory, applying the correct label may be a CCP, because a customer with an allergy relies on it and no later step will correct it.

If a significant hazard has no control at any step, the product or process should be changed. Once CCPs are decided, mark them on the flow diagram and list them in a table.