The Hazard Analysis Process in ISO 22000: A Step by Step Walkthrough

Why Hazard Analysis Is the Heart of ISO 22000

If you are working with ISO 22000 or preparing for a food safety certification audit, hazard analysis is the process you cannot afford to get wrong. It is the technical engine that drives everything else in the food safety management system. Get it right and your controls make sense. Get it wrong and your entire HACCP plan sits on shaky foundations.

ISO 22000 requires organisations to conduct a systematic hazard analysis before establishing any control measures. This is not a one time exercise done during implementation and then filed away. It is a living process that must be updated whenever products, processes, ingredients, or operating conditions change. Auditors will test whether your hazard analysis is current, credible, and actually connected to the controls your team uses on the floor.

This walkthrough covers the full hazard analysis process under ISO 22000, from assembling your food safety team through to determining control measures. Whether you are a quality manager building the system for the first time, an internal auditor preparing to review it, or someone adding food safety to their auditor skill set, this guide will give you the practical detail you need. For a broader overview of the standard itself, see our post on what ISO 22000 is and who needs it.

Step 1: Assemble the Food Safety Team

Hazard analysis is not a job for one person sitting at a desk. ISO 22000 Clause 7.3 requires the organisation to establish a food safety team with the necessary combination of knowledge and experience. This team must have multi-disciplinary coverage, meaning people who understand the products, the processes, the equipment, and the regulatory environment.

In practice, a food safety team for a meat processing facility might include a production supervisor, a quality technician, a maintenance engineer, a procurement officer, and the food safety manager. Each person brings a different lens. The production supervisor knows where the line slows down and where staff cut corners. The maintenance engineer knows which pieces of equipment have dead zones that are hard to clean. The procurement officer knows which suppliers have had quality issues.

The team leader, often called the food safety team leader, carries specific responsibilities under the standard. This person must ensure the food safety team is established, trained, and that the food safety management system is implemented, maintained, and updated. They are the key contact point for the certification body.

What Auditors Look For at This Step

When auditing the food safety team requirement, auditors will ask to see documented evidence of who is on the team, what qualifications and experience each member has, and how the team was formed. They will look for training records, job descriptions, and meeting minutes. If the entire hazard analysis appears to have been done by one person with no input from operations, that is a red flag. Expect questions about how the team was involved in the process.

Step 2: Describe the Products and Their Intended Use

Before you can identify hazards, you need a complete picture of what you are making and who will eat it. ISO 22000 Clause 8.5.1 requires product descriptions that cover all relevant food safety information. This includes raw materials, ingredients, and contact materials, as well as the characteristics of finished products.

For raw materials and ingredients, you need to document biological, chemical, and physical characteristics, the origin of the material, the method of production, the method of delivery and packaging, storage conditions, shelf life, preparation and handling before use, and any food safety related acceptance criteria. For finished products, you need similar detail plus information about how the product is intended to be used, including any unintended but reasonably expected misuse.

The intended use description is particularly important. A ready to eat product consumed without further cooking has a very different hazard profile than a product that will be cooked by the consumer. A product marketed to immunocompromised individuals requires stricter controls than a product for the general healthy adult population. These distinctions directly affect which hazards are significant and what control levels are acceptable.

A Practical Example

Consider a manufacturer producing chilled, ready to eat coleslaw. The product description would note that the product contains raw cabbage, carrot, and a mayonnaise based dressing. It is sold in modified atmosphere packaging with a refrigerated shelf life of 14 days. The intended consumer is the general population, including elderly people and pregnant women who may purchase it from supermarkets. No further cooking is expected. This immediately signals that Listeria monocytogenes is a critical biological hazard that must be addressed rigorously in the hazard analysis.

Step 3: Construct Flow Diagrams

ISO 22000 Clause 8.5.1.5 requires the food safety team to construct flow diagrams for the products and processes covered by the food safety management system. A flow diagram is a schematic representation of the sequence and interaction of steps in the production of a product. It must be sufficiently detailed to be useful for hazard analysis.

The flow diagram needs to show every step in the process, from receipt of raw materials through to dispatch of finished product. It should also include rework loops, where product is returned to an earlier stage of the process. It should show where water, energy, and packaging materials enter the process. Cross contamination pathways, such as where raw and ready to eat products share equipment or pass through the same area, must be visible in the diagram.

Critically, the flow diagram must be verified on site. The food safety team leader or a team member must walk the production floor and confirm that the diagram matches what actually happens. This is called on site confirmation of the flow diagram, and it is a specific requirement under Clause 8.5.1.5. Diagrams drawn in an office and never checked against reality are a common source of nonconformities. Auditors will ask whether the diagram was verified, by whom, and when.

Step 4: Conduct the Hazard Analysis

This is the core of the process and the step that requires the most technical rigour. ISO 22000 Clause 8.5.2 sets out the hazard analysis requirements in detail. The process involves three distinct activities: hazard identification, hazard assessment, and selection of control measures.

Hazard Identification

The food safety team must identify all food safety hazards that are reasonably expected to occur in relation to the product type, the type of process, and the process facilities. Hazards fall into three main categories.

• Biological hazards include bacteria such as Salmonella, E. coli O157:H7, Listeria monocytogenes, and Campylobacter, as well as viruses, parasites, and prions. These are the hazards most commonly associated with serious foodborne illness outbreaks.
• Chemical hazards include naturally occurring toxins such as mycotoxins and allergens, agricultural chemicals such as pesticide residues, processing contaminants such as acrylamide, and cleaning chemical residues.
• Physical hazards include foreign objects such as metal fragments, glass, bone, plastic, and wood that could cause injury or illness if consumed.

The identification step should be exhaustive. The team should consider every ingredient, every process step, every piece of equipment, every person who handles the product, and every environmental condition that could introduce a hazard. Reference to regulatory requirements, scientific literature, historical incident data, and customer complaints can all support this step.

Allergen management deserves special mention. The major food allergens, including peanuts, tree nuts, milk, eggs, wheat, soy, fish, and shellfish, must be identified as chemical hazards wherever they are present in ingredients or where cross contact is possible. This is an area of increasing regulatory scrutiny in Australia, and auditors will look closely at how allergens are managed through the hazard analysis and into the control measures.

Hazard Assessment

Once hazards are identified, the team must assess each one to determine whether its prevention or reduction to acceptable levels is essential to the production of safe food. ISO 22000 requires this assessment to consider two factors: the likelihood of occurrence of the hazard prior to control measures, and the severity of the adverse health effects in relation to the intended use.

This is essentially a risk assessment, though ISO 22000 uses the term hazard assessment rather than risk assessment to align with food safety terminology. The output of the hazard assessment is a determination of whether a hazard is significant. Significant hazards are those where the combination of likelihood and severity is high enough that they must be managed through the food safety control system.

Many organisations use a simple matrix to document this assessment, with likelihood on one axis and severity on the other. The matrix should be defined by the food safety team and applied consistently across all hazards. The rationale for each assessment decision should be documented. Auditors will probe the reasoning behind these decisions, particularly where a hazard has been assessed as not significant. If the justification is weak, the assessment may not stand up to scrutiny.

Selection of Control Measures

For each significant hazard, the food safety team must select appropriate control measures. ISO 22000 distinguishes between two types of control measures based on where they sit in the system.

Prerequisite programmes, or PRPs, are the foundational conditions and activities necessary to maintain a hygienic environment throughout the food chain. These include cleaning and sanitation, pest control, personal hygiene, supplier control, and maintenance of equipment. PRPs manage hazards that are present across the entire operation rather than at specific process steps.

Operational PRPs, or OPRPs, are control measures that are more specific than standard PRPs but do not meet the criteria for a critical control point. An OPRP might control a hazard through monitoring and corrective action but without the strict critical limits and verification requirements of a CCP.

Critical control points, or CCPs, are steps in the process where a control measure can be applied and is essential to prevent or eliminate a food safety hazard or reduce it to an acceptable level. Classic examples include pasteurisation to eliminate pathogenic bacteria in liquid products, metal detection to identify and remove metal fragments, and cook steps to achieve a required internal temperature. For a deeper look at how PRPs and CCPs relate to each other, see our article on PRPs and CCPs explained.

Step 5: Establish the HACCP Plan

For each CCP identified in the hazard analysis, the HACCP plan must document specific information. ISO 22000 Clause 8.5.4 sets out what the HACCP plan must contain for each CCP.

• The food safety hazard controlled at the CCP. This links the CCP back to the hazard analysis and makes clear what the CCP is there to manage.
• Critical limits. These are the measurable boundaries that separate acceptable from unacceptable at the CCP. A critical limit must be measurable and must be validated to confirm that it actually controls the hazard. Examples include a minimum internal temperature of 75 degrees Celsius for a cook step, a maximum metal fragment size detectable by the metal detector, or a minimum water activity level for a dried product.
• Monitoring procedures. The HACCP plan must specify how the CCP will be monitored, who will do it, how often, and using what method. Monitoring must be capable of detecting loss of control at the CCP in time to prevent unsafe product from reaching consumers.
• Corrections and corrective actions. The plan must specify what happens when monitoring shows that a CCP is out of control. Corrections deal with the immediate situation, such as isolating product produced during the period of deviation. Corrective actions address the root cause to prevent recurrence.
• Responsibilities and authorities. The plan must assign responsibility for monitoring, for taking corrections, and for recording results.
• Records. The HACCP plan must specify what records will be kept to demonstrate that the CCP is under control.

Step 6: Validate Control Measures

Validation is a requirement that many organisations underestimate. ISO 22000 Clause 8.5.3 requires that control measures, or combinations of control measures, be validated prior to implementation and after any change. Validation means confirming that the control measure is actually capable of controlling the hazard to the required level.

Validation is different from verification. Validation answers the question: can this control measure work? Verification answers the question: is it working? Both are required, but they happen at different points and serve different purposes.

For a cook step, validation might involve challenge testing with a target pathogen, review of published scientific literature on thermal inactivation, or reference to regulatory guidelines on minimum cook temperatures. The validation evidence must support the critical limits set in the HACCP plan. If the critical limit is a minimum internal temperature of 75 degrees Celsius, the validation evidence must demonstrate that this temperature achieves the required log reduction of the target pathogen in the specific product being produced.

Auditors will ask to see validation records for each CCP. Where organisations have relied on generic industry guidelines rather than product specific validation, auditors will probe whether those guidelines are applicable to the specific product, process, and pathogen in question.

Step 7: Establish Verification Activities

ISO 22000 Clause 8.8 requires the organisation to establish, implement, and maintain verification activities. Verification confirms that the food safety management system, including PRPs, OPRPs, and the HACCP plan, is working as intended.

Verification activities include internal audits of the food safety management system, review of CCP monitoring records, calibration of monitoring equipment, and microbiological testing of finished products or environmental samples. The results of verification activities must be analysed to confirm that the overall system is effective.

A common finding in food safety audits is that verification activities exist on paper but are not actually being carried out systematically. Auditors will sample verification records and look for evidence that the activities are happening at the required frequency, that results are being reviewed, and that deviations are triggering appropriate responses. For practical guidance on running effective food safety internal audits, see our post on running effective food safety internal audits.

Common Hazard Analysis Nonconformities

Having conducted and observed many food safety audits, certain hazard analysis failures come up repeatedly. Being aware of these helps both practitioners building the system and auditors reviewing it.

• Hazard analysis not updated after process changes. A new ingredient, a new piece of equipment, a new supplier, or a change in the production layout can all introduce new hazards. If the hazard analysis is not reviewed and updated to reflect these changes, it no longer reflects the actual operation.
• Flow diagrams not verified on site. Diagrams that were created during implementation and never walked against the actual process are common. They often miss rework loops, cross contamination pathways, or steps that have been added since the original implementation.
• Hazard assessment rationale not documented. When auditors ask why a hazard was assessed as not significant, the team cannot explain the reasoning. The decision may have been correct, but without documented rationale it cannot be verified.
• Critical limits not validated. Limits have been set based on habit or assumption rather than scientific evidence. This is particularly common for cook temperatures and metal detector sensitivity settings.
• Allergen hazards missing from the analysis. Allergens are sometimes treated as a separate topic rather than being integrated into the hazard analysis. Under ISO 22000, they are chemical hazards and must be assessed accordingly.
• OPRPs and CCPs confused. Organisations sometimes classify controls as CCPs when they meet the criteria for OPRPs, or vice versa. The distinction matters because the monitoring, verification, and documentation requirements differ between the two.

Keeping the Hazard Analysis Current

ISO 22000 requires the hazard analysis to be updated whenever changes occur that could affect food safety. This is not limited to major changes. A new cleaning chemical, a change in a supplier's processing method, a modification to packaging, or even a change in the intended consumer group can all have food safety implications that need to be assessed.

The most effective organisations treat hazard analysis as a continuous activity rather than a periodic document review. The food safety team meets regularly to review any changes in the operation, assess their food safety implications, and update the hazard analysis and control measures as needed. These meetings should be documented, and the hazard analysis should carry a revision history that shows when it was updated and why.

Auditors will check the revision history of the hazard analysis against the organisation's change records. If significant changes to the operation have occurred since the last revision of the hazard analysis, that is a strong indicator that the system is not being maintained as required.

Building Your Food Safety Auditor Skills

Understanding the hazard analysis process is essential for anyone auditing food manufacturing, food service, or food distribution operations against ISO 22000. It is a technically demanding area that requires both an understanding of the standard's requirements and a working knowledge of food science and food safety principles.

If you are looking to add ISO 22000 to your auditor skill set or prepare for a food safety certification audit, Audit Workshop offers training that covers the standard's requirements with the practical depth that food safety auditing demands. Our courses are built for practitioners who need to understand not just what the standard says, but how to apply it in real food production environments.