How to Monitor Critical Control Points

Once you have established critical control points (CCPs) and critical limits for your HACCP plan, you need to monitor them. Monitoring must provide real-time data. Therefore microbial sampling and testing is not considered part of the HACCP monitoring plan. They cannot give you immediate feedback and are generally inefficient in identifying defects. In  creating your monitoring plan, the primary questions to consider are what will be done, how will it be done, when, or how frequent, it will be done, and who will do it?

What Will Be Done?

You will know “what” to monitor based on the type of critical limits that have been set for your CCPs. For example, if a critical limit is pH of no greater than 4.6, then pH is what you would be monitoring. Other attributes that you may monitor in a HACCP plan may include time, temperature, acidity, flow rate and pressure.

How Will it Be Done?

There are essentially two general ways to monitor critical limits. One is by visual observation and the other is by instrumentation. An example of a visual check is to ensure that sieves or metal detectors are in place and are not blocked. Operators conducting visual observations should be properly trained to know what they are looking for and when critical limits are exceeded. If instrumentation is used to monitor CCPs, then monitors must make sure to:

1. Use the right instrument for the job. For example, don’t use a laser thermometer to measure the internal cooking temperature of roasted turkey since that instrument will only give you the surface temperature.
2. Follow the right procedures to use the instrument.
3. Calibrate the instrument to ensure accuracy, precision, and validity of data.

When Will it Be Done?

In general, monitoring will be done either continuously or discontinuously. In  continuous monitoring you are collecting data throughout the entire period of the operation. In discontinuous monitoring, the measurements are collected or observations made periodically. Continuous monitoring is generally done automatically by instruments. This type of data collection is necessary when slight deviations from the critical limit can be easily missed by the operator. Let’s say that the critical limit for cooking canned soup is holding the temperature at 240^oF for 10 minutes. What if during the process of one batch, the temperature were to drop to 239^oF for 40 seconds? This is a deviation that could easily be overlooked, putting  consumers at risk. Hence it is necessary to collect data continuously. In the canning industry, temperature/time data is collected using a automatic recording chart that the operator can later review to verify that the cooking conditions were met.

Continuous monitoring is not always suitable or practical. In these cases, a discontinuous monitoring approach may be adopted. A discontinuous monitoring plan is suitable when:

1. The critical limit is to be measured by observation e.g. checking  sieves. If the operator were to monitor the sieves continuously, there would be time to do nothing else.
2. The operating condition is way above the critical limit. For example, if your critical limit for oil temperature in your fryer is at “least 300^oF”, and you are frying at 350^oF for quality reasons, then discontinuous temperature measurement is acceptable.
3. When continuous measurement is not necessary to assure safety. For example, there is no need to check the temperature of turkey minute-by-minute during roasting if the critical limit is “a minimum internal temperature of 165 ^oF”. All you would need to do in this case is to check the temperature at the end.

Who Will Do it?

The person responsible to conduct monitoring will be identified in the HACCP plan by his title. For example, “Quality Control Supervisor”. Otherwise, to allow more flexibility, the phrase “or designated personnel” may be added. Whoever this designee is, he must be aware of this duty and must be trained to the same level as the usual monitor, to carry out the responsibility effectively when required.

Introduction to HACCP eBook

Reference: Scott, V. N. & Stevenson, K. E. (2006). HACCP – A systematic approach to food safety, 4th edition. Washington, DC: Grocery Manufacturers Association.