FOOD SAFETY AND QUALITY ASSURANCE: HACCP AND PREREQUISITE PROGRAMMES
Diagram
For each hazard, ask in order
Can a control at this step prevent, remove, or reduce the hazard to a safe level, and will no later step do it?
↓
Yes, and no later step will do it: this step is a CCP
The control is essential, but it is not a CCP: this step is an OPRP
General hygiene and good practice: this is a PRP
Figure 1: The decision tree sorts each control into a CCP, an OPRP, or a PRP, and the HACCP plan must say which programme controls each hazard.
Introduction
CCP and OPRP are the two kinds of control that sit at the centre of a food safety plan, and students often mix them up. A CCP, a critical control point, is a step where control can be applied to prevent, remove, or reduce a hazard to a safe level, and where no later step will do that job. An OPRP, an operational prerequisite programme, is a control measure that is essential for food safety but is not a CCP. The milk line shows the difference: pasteurisation is a CCP because it kills the microbes, while the checks at milk receiving are PRPs and OPRPs, because later pasteurisation removes the bacteria.
Table 1: Quick comparison of CCP and OPRP
| Aspect | CCP | OPRP |
|---|---|---|
| Full name | Critical control point | Operational prerequisite programme |
| Definition | A step where control can prevent, remove, or reduce a hazard to a safe level | A control measure that is essential for food safety but is not a CCP |
| Where it sits | In the HACCP plan | In the OPRP plan, beside the HACCP plan, in the hazard control plan of ISO 22000 |
| Limit set | A critical limit: a maximum or minimum value that must not be missed | An action criterion: a measurable value that shows the control is working |
| Monitoring | Watched while the step runs, often continuously | Watched at set times, as the plan states |
| If the limit is missed | Corrective action at once, and the product is held | Corrective action as the plan states, and the product is checked |
| Example | Heating milk at the pasteuriser, where the time and temperature kill microbes | Washing vegetables, which reduces germs but does not fully remove them; a filler seal check |
| Decision test | If a later step will control the hazard, this step is not a CCP | If the control is essential yet no critical limit fits it, it is an OPRP, not a CCP |
Scientific explanation
Definition
A critical control point (CCP) is a step where control can be applied to prevent, remove, or reduce a hazard to a safe level. Not every step is a CCP: heating milk is a CCP, because it kills the microbes of concern, while storing a sealed pack is usually not a CCP, because no control at that step removes a hazard. An operational prerequisite programme (OPRP) is a control measure that is essential but is not a CCP, such as a washing step for vegetables that reduces germs but does not fully remove them.
Working principle
A CCP works through the seven HACCP principles: the hazard is listed, the CCP is found with a decision tree, a critical limit is set, monitoring watches the limit, corrective action follows a miss, verification checks the system, and records prove it. An OPRP works as part of the hazard control plan: the hazard analysis names it, the plan states its action criterion and its monitoring, and verification checks that it works. The HACCP plan must say, for each hazard, which programme controls it: PRP, OPRP, or CCP.
Apparatus
At a CCP the instruments are the tools of the step, such as a thermometer and a clock at a pasteuriser. At an OPRP the tools depend on the step, such as a check on a filler seal or a wash water test.
Measurement procedure
CCP monitoring checks the critical limit while the step runs, such as reading the pasteuriser temperature every hour, and writes the result down. OPRP monitoring checks the action criterion at the times the plan states, and writes the result down. In both cases a failed check starts a corrective action.
Factors affecting readings
Readings change with the instrument, the food, and the person. A thermometer that reads true, a clock that is checked, and staff who record at the time, not from memory at the end of the shift, are what make the numbers honest.
Formulas and calculations
This topic has no standard formula in the books used for this article, so no worked example is given here. Do not use a made up formula for this topic.
Industrial applications
- CCP: pasteurisation of milk, cooking of meat, metal detection at the end of a line, and chilling of cooked food.
- OPRP: washing of vegetables, checks on filler seals, supplier approval and temperature checks at receiving, and cleaning checks between allergen runs.
- Both: a milk plant runs pasteurisation as its CCP and receiving checks as PRPs and OPRPs in one hazard control plan.
Advantages and limitations
CCP advantages: clear limit, clear watch, and clear action when the limit is missed, so safety is decided at one named step. Limitations: only a few steps can be CCPs, so a plan with too many CCPs is hard to watch, and a plan with a missed CCP is unsafe.
OPRP advantages: covers essential controls that do not fit a critical limit, so the plan stays honest about what really controls each hazard. Limitations: an OPRP is easier to run loosely than a CCP, so its monitoring and action criteria must be written down and checked.
FAQ
How do I know if a step is a CCP?
Use the decision tree: if a later step will control the hazard, this step is not a CCP. If no later step will control it, and control here is possible, this step is a CCP.
Can washing vegetables be a CCP?
Usually not. Washing reduces germs but does not fully remove them, so it is an OPRP. A later cooking step that kills the germs would be the CCP.
What is the difference between a critical limit and an action criterion?
A critical limit is the line a CCP must not cross. An action criterion is the measurable value that shows an OPRP is working.
Where do CCPs and OPRPs sit in ISO 22000?
Together in the hazard control plan, which is the HACCP plan and the OPRP plan together.
References and further reading
- FTN subject Food Safety and Security, Unit 4: HACCP and Prerequisite Programmes, and Unit 5: Food Safety Management Systems and Food Law.
- FTN subject Food Quality Control and Standards, Unit 12: HACCP, Food Safety Management Systems, Audits and Certification, section 12.2 on the seven principles.
- Book on disk: Food Quality Assurance: Principles and Practices.
- Google Books: Sara E. Mortimore, HACCP: A Food Industry Briefing, which sets out the seven HACCP principles.
