HACCP: the seven principles
How HACCP works: origins, prerequisite programmes, the 12 Codex steps and 7 principles, CCPs and critical limits, with a worked pasteuriser example.
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Testing finished food cannot guarantee safety: only a tiny sample is ever tested, and by the time a problem is found the food may already be eaten. Hazard Analysis and Critical Control Points (HACCP) takes the opposite approach: it identifies the hazards at each step of making a food, and puts controls where they matter most, so that problems are prevented rather than detected afterwards. HACCP is now required or expected for food businesses in most countries and underpins international food trade.
HACCP principles and their application are core topics in food safety, food technology and dairy technology exams.
Origins
HACCP was developed in the 1960s by the Pillsbury Company with NASA and the US Army Natick laboratories, to make food for astronauts as close to 100 per cent safe as possible. It spread to low-acid canned foods in the United States in the 1970s, and in 1993 the Codex Alimentarius Commission adopted guidelines for applying HACCP, now part of the Codex General Principles of Food Hygiene (CXC 1-1969, revised in 2020).
Hazards
A hazard is a biological, chemical or physical agent in food with the potential to cause harm:
- Biological: pathogenic bacteria, viruses, parasites and their toxins.
- Chemical: pesticide and veterinary drug residues, mycotoxins, cleaning chemicals, allergens, heavy metals and process contaminants.
- Physical: glass, metal, stones, bone and wood fragments.
Allergens are often managed as a separate category because undeclared allergens are a leading cause of food recalls.
Prerequisite programmes
HACCP works only on a foundation of good hygiene practices (GHP), also called prerequisite programmes: hygienic premises and equipment, cleaning and disinfection, pest control, safe water, personal hygiene and training, supplier control, temperature control, waste management and traceability. These control general hazards; HACCP focuses on specific significant hazards in the process.
The 12 steps and 7 principles
Preliminary steps: assemble a multidisciplinary HACCP team; describe the product (composition, processing, packaging, storage, shelf life); identify its intended use and consumers (including vulnerable groups); draw a process flow diagram; and confirm it on site.
The seven principles:
- Conduct a hazard analysis: list hazards at each step, assess their likelihood and severity, and identify control measures.
- Determine critical control points (CCPs): steps where control is essential to prevent, eliminate or reduce a significant hazard to an acceptable level, such as cooking, pasteurisation, chilling, acidification or metal detection. A decision tree helps.
- Establish critical limits for each CCP: measurable values separating acceptable from unacceptable, such as a temperature, time, pH or water activity.
- Establish monitoring procedures: what is measured, how, how often and by whom, ideally continuously.
- Establish corrective actions when monitoring shows a deviation: regaining control and dealing with affected product.
- Establish verification: checks that the system works, such as calibration, record reviews, sampling and audits; validation shows that control measures are capable of controlling the hazard.
- Establish documentation and record keeping.
Common mistakes
- Copying a generic plan without walking the actual process.
- Declaring too many CCPs, which dilutes attention, or too few.
- Critical limits that are vague, such as "cook well", instead of measurable values.
- Monitoring records filled in afterwards rather than at the time.
- Not training staff, or not reviewing the plan after changes in recipes, equipment or suppliers.
HACCP in practice
- Food safety management systems such as ISO 22000 and certification schemes recognised by the Global Food Safety Initiative build on HACCP.
- Small businesses use simplified, flexible approaches, such as guides for restaurants and street food.
- HACCP is a living system: it must be reviewed when products, suppliers, equipment or regulations change.
A CCP at the pasteuriser
In a milk plant, the hazard analysis identifies vegetative pathogens in raw milk (Salmonella, Listeria, pathogenic E. coli, Coxiella) as significant. Pasteurisation is the step that eliminates them, so it is a CCP.
| Element | Example |
|---|---|
| Critical limit | at least 72 °C for at least 15 s (HTST) |
| Monitoring | continuous temperature recording at the end of the holding tube; flow rate checked |
| Corrective action | flow diversion valve automatically returns under-heated milk; investigate cause; hold and assess any affected product |
| Verification | daily chart review, thermometer calibration, alkaline phosphatase tests, periodic validation of holding time |
| Records | temperature charts, diversion events, calibration and test results |
Hazard scoring. Many teams score likelihood and severity from 1 to 3 and treat hazards scoring 6 or more (likelihood × severity) as significant. Glass fragments from a bottle line, likelihood 2 and severity 3, score 6: significant, controlled by a glass policy and inspection. Dust on outer cartons, likelihood 2 and severity 1, scores 2: handled by prerequisite cleaning.
Key points
- HACCP prevents hazards by controlling them at critical points, rather than relying on end-product testing.
- Developed for NASA in the 1960s; Codex guidelines from 1993, revised in 2020.
- Hazards are biological, chemical (including allergens) and physical.
- Prerequisite programmes (good hygiene practices) are the foundation.
- 12 steps: five preliminary steps plus seven principles: hazard analysis, CCPs, critical limits, monitoring, corrective actions, verification, records.
- CCP examples: cooking, pasteurisation, chilling, acidification, metal detection.
What the exams ask
- School-leaving and entrance papers: what HACCP stands for and its principles.
- Degree and research-fellowship entrances: preliminary steps, the seven principles, CCP decision trees, critical limits, verification and validation, and prerequisite programmes.
- Food safety examinations: developing HACCP plans for specific products, auditing, and linking HACCP with ISO 22000 and regulatory requirements.
Described in general terms: the kind of examination, not a past paper. Laisha never reproduces exam questions.
Questions people ask
Is every important step a CCP?
No. A CCP is a step where control is essential and no later step will remove the hazard. Many hazards are controlled by prerequisite programmes rather than CCPs.
What is the difference between verification and validation?
Validation asks whether a control can work, such as proving a cooking time and temperature kills the target pathogen. Verification asks whether the plan is being followed and working, through checks, records and testing.
Does HACCP apply to farms?
HACCP principles are used in some on-farm assurance schemes, but farms mainly rely on good agricultural and hygiene practices. HACCP is mandatory mostly in food processing and food service.
Sources
- Codex Alimentarius Commission. General Principles of Food Hygiene (CXC 1-1969), revised 2020. FAO and WHO.
- Mortimore, S. and Wallace, C. HACCP: A Practical Approach, 3rd edition. Springer, 2013.
- National Advisory Committee on Microbiological Criteria for Foods. "Hazard analysis and critical control point principles and application guidelines." Journal of Food Protection 61, 1246–1259 (1998).
- ISO 22000:2018. Food Safety Management Systems: Requirements for Any Organization in the Food Chain. International Organization for Standardization.
- Ross-Nazzal, J. "From farm to fork: how space food standards impacted the food industry and changed food safety standards." In Dick, S. J. and Launius, R. D. (eds) Societal Impact of Spaceflight. NASA, 2007.
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