Determining critical control points and their critical limits
Determining if there are Critical Control Points (CCPs) in your process and establishing critical limits for these CCPs are essential steps in the development of a Preventive Control Plan (PCP) that will effectively control hazards significant for your food. They are also the second and third principles of a Hazard Analysis Critical Control Point (HACCP) system.
A CCP is a step in your process where a control measure with clear critical limit(s) is essential to control a significant hazard. Critical limits are the measurable or observable pre-set values or criteria that separate what is acceptable from what is not acceptable to achieve food safety.
The Canadian Food Inspection Agency (CFIA) created this document as guidance to help food businesses comply with the requirements of the Safe Food for Canadians Regulations.
Note: This guidance was written with the assumption that you have already conducted a complete hazard analysis of the inputs, processing steps and traffic flows and identified all biological, chemical and physical hazards.
It's your choice
You may use other guidance developed by provincial governments, industry associations, international partners or academic bodies as long as they can achieve the same outcome. Always ensure that the guidance you choose is relevant for your particular business, product or products, and market requirements.
What is included
- outlines the steps involved in determining CCPs
- provides examples of templates that can be used to determine CCPs
- provides generic criteria and examples that outline the steps involved in establishing critical limits for CCPs
Refer to the Tell me more! section for additional sources of information that may help you determine the CCPs.
What is not included
The templates provided may not be applicable to all situations and the examples provided are not exhaustive.
Other approaches not discussed may be used to determine CCPs and their critical limits.
Roles and responsibilities
Food businesses are responsible for complying with the law. They demonstrate compliance by ensuring that the commodities and processes for which they are responsible meet regulatory requirements. If a written PCP is required, the food business develops a PCP with supporting documents, monitors and maintains evidence of its implementation, and verifies that all control measures are effective.
The CFIA verifies the compliance of a food business by conducting activities that include inspection and surveillance. When non-compliance is identified, the CFIA takes appropriate compliance and enforcement actions.
Determining critical control points
CCPs are the steps in your process where a control measure is or can be applied and is essential to prevent, eliminate or reduce to an acceptable level the identified food safety hazard(s). You can determine CCPs with the help of a question and answer template or a decision tree to individually assess the biological, chemical and physical hazards identified during your hazard analysis.
The questions are designed to guide you through the process, as you will see in the examples provided in the next two sections. Keep in mind:
- More than one step in a process may be involved in controlling a hazard
- More than one hazard may be controlled by a specific control measure
- It is important to keep any supporting documents that can justify the rationale for your answers
In a typical establishment, the location of hazards and the number of CCPs depend on the equipment, plant layout, ingredients, process used, and many other factors. Some traditional processing steps that food processors have determined to be CCPs include:
Critical Control Point determination templates
With the Critical Control Point determination template in the Preventive control plan templates – For domestic food businesses you would list the process steps for which you identified a significant hazard(s) and follow a series of questions to guide you through the process of identifying critical control points.
In the Food Safety Enhancement Program approach to PCP, another type of template (Form 8) is used to determine CCPs and other control measures. In this template, all hazards at every steps of the process are assessed through a series of questions.
Decision tree template
A decision tree asks a series of questions which are designed to guide you through the process of determining CCPs.
The following is an example of a decision tree developed by Codex. Other examples of decision trees based on Codex are available. It is important to select a decision tree that best suits your operation.
Establishing critical limits for a CCP
After identifying the CCPs in your process, you need to define the critical limits that have to be met at this step to ensure that a hazard is prevented, eliminated or reduced to an acceptable level. It is important that your critical limits:
- be supported by scientific data
- meet Canadian standards and guidelines as applicable
|Time and temperature
|Time and temperature
|Concentration (ppm), pH
|Water activity (Aw)
|Freezing for parasite control
|Time and temperature
Characteristics of a critical limit
Critical limits should be specific and measurable. An evaluation of a critical limit should produce an immediate result to ensure a quick decision on whether the identified hazard is controlled to an acceptable level.
Critical limits may be quantitative (for example, length, height, area, volume, weight, speed, time, temperature, humidity) or qualitative (for example, other types of properties that can be confirmed by a visual inspection, such as colour of the food or presence of air bubbles). Provide the rationale that supports the critical limits you establish (scientific data, Regulatory requirement). Critical limits which are based on qualitative data should be supported further with descriptions/instructions that help those responsible for monitoring the CCP to understand the critical limit and apply it uniformly.
Ongoing evaluation of your CCPs ensures that the critical limits, which are measurable criteria, are met. When you can demonstrate that food production has stayed within critical limits you are confirming the safety of the food product.
Critical limits with a combination of criteria
In some cases, you may need to use more than one critical limit to control a hazard at a particular CCP. Such critical limits would be a set of criteria, such as temperature, time (minimum time exposure), physical product dimensions, water activity and moisture level.
The following example demonstrates a combination of criteria as critical limits.
For beef patties cooked in a continuous oven, the hazard of pathogen survival could be controlled with the following combination of criteria as critical limits:
- minimum internal temperature of the patty
- oven temperature
- time in the oven determined by the belt speed rpm and patty thickness
Critical limits when there's more than one hazard to control
In some cases, you may identify more than one hazard for a CCP. In these cases, you may need different critical limits to control each hazard.
- At a vegetable washing step identified as a CCP because of a significant biological and chemical hazard, separate critical limits would be needed to control each of the hazards. A critical limit of 100 ppm of chlorine in wash water can be established to control biological hazards, and a critical limit of no more than 150 ppm of chlorine can be established to control the chemical hazard.
How to establish critical limits
Step 1: Determine critical limit(s) for each CCP
For each hazard identified during the hazard analysis associated with a CCP, you need to determine the criteria that prevent, eliminate or reduce the hazard to an acceptable level.
The following are examples of criteria for a critical limit:
- a minimum temperature and time that must be achieved to ensure destruction of a pathogenic bacteria
- a specific pH to prevent the growth of bacteria
- a level of a preservative to control the growth of bacteria
- the minimum size of detectable foreign substances to prevent extraneous matter hazards
You may obtain criteria from many sources:
- regulatory standards and guidelines
- review of published research documents
- experimental results (for example, in-house experiments, contract laboratory studies)
- experts (for example, thermal process authorities, consultants, food scientists, microbiologists, equipment manufacturers, sanitarians, academics)
- industry best practice
The following are examples of critical limits specified in regulations that you must apply:
- potassium nitrate that is added alone or in combination with sodium nitrate to dry sausage shall not exceed 200 parts per million: Food and Drug Regulations, C.R.C., c. 870, s. B.16.100
- milk or whole milk shall contain added vitamin D in such an amount that a reasonable daily intake of the milk contains not less than 300 International Units and not more than 400 International Units of vitamin D: Food and Drug Regulations, s. B.08.005
Step 2: Obtain evidence that shows each critical limit is effective in controlling the hazard
This step needs to be documented and the documentation supporting the validation retained. You can find more specific details on validation of control measures and critical limits in the document Evidence showing a control measure is effective.
Step 3: Implement and monitor the validated critical limits at the CCP to ensure that the food safety hazard is controlled
Monitoring is important because unforeseen factors can make control measures ineffective. Plan for and document the corrective actions to be taken when your monitoring results indicate that the critical limit is not met.
Keep in mind
Critical limits may need to be re-evaluated, re-established and re-validated when you make changes to a production line (for example, line speed, process step addition or elimination, new equipment), adjust a formulation (for example, higher concentration of pathogens in the new ingredient or food) or learn new information (for example, a previously unidentified hazard, change to accepted practice).
Tell Me More! Further reading
The following references contain information that helps explain food safety controls, demonstrates how to develop them, and provides examples. The CFIA is not responsible for the content of documents that are created by other government agencies or international sources.
- Preventive control plan templates – For domestic food businesses
- Step-by-step guide for domestic food businesses: Preparing a preventive control plan
- Conducting a hazard analysis
- Corrective actions
- Monitoring procedures
- Codex Alimentarius Commission, General Principles of Food Hygiene, CXC 1-1969, 2020
- International Commission on Microbiological Specifications for Foods (ICMSF). Microorganisms in Foods 4: Application of the Hazard Analysis Critical Control Point (HACCP) System to Ensure Microbiological Safety and Quality, Oxford: Blackwell Scientific Publications, 1988
- Food safety standards and guidelines
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