Critical Limits

When a hazard requires a preventive control, the intervention must reduce risk to a certain amount, called a critical limit, to ensure that the hazard is significantly minimized or eliminated.

 If the risk isn’t reduced down to that limit, the step is out of control and may pose a risk to consumers’ health.

There are many different types of critical limits, and they must be specific for the CCP and the hazard. Examples of parameters with critical limits are temperature, flow rate, line speed, product bed depth, weight, and others depending on the process. There can be more than one critical limit per hazard such as the amount of time product is at a certain temperature. Here are the critical limits for our roasting step example:

Process Control form – Critical Limits (FSPCA, (2016). Food Safety Plan for Peanut Butter – Teaching Example, page 10)

Based on scientific studies, experts have determined these actions will reduce the hazard (Salmonella) to a safe level.

There are many sources of information on critical limits. These include regulations, guidelines, performance standards, tolerances and actions levels from regulatory and government agencies. 

  • Regulations are laws regarding food safety in the country that produces or imports the particular food. For example, many countries have a regulation that states that food should be free from pathogenic bacteria. 
  • Guidelines offer detailed explanation of how to comply with a food safety regulation, such as the U.S. guideline for clean peanut butter. 
  • Performance standards, tolerances, and action levels are published food safety limits that may apply to your food such as the maximum metal particle size allowed.  

Trade associations, process authorities, industry scientists, university and extension scientists, and consultants may help to set critical limits. 

Scientific studies can be conducted in-house, at a contract laboratory or a university. Information is often available from peer-reviewed scientific literature. The data for critical limits for roasting peanuts was obtained from a scientific study conducted by the American Peanut Council and published in a peer-reviewed journal.