PFA Level 2 Food Safety cheat sheet

Four hazard classes: biological (bacteria, viruses, parasites, moulds), chemical (cleaning agents, pesticides, toxins), physical (glass, metal, bone, pests), allergenic (proteins from 14 regulated sources).

Contamination routes: direct (raw to ready-to-eat contact), indirect (hands, utensils, surfaces, cloths), cross-contamination via drip, splash, aerosols and shared equipment.

Biological hazards cause most foodborne illness; bacteria need moisture, protein, suitable pH (above 4.6 for most pathogens) and time-temperature abuse to multiply.

Multiplication maths: binary fission roughly every 20 minutes in the danger zone; 1 cell can become over 1 million in about 7 hours (about 20 generations).

Spore-formers (Clostridium, Bacillus) survive cooking; toxin producers may leave heat-stable toxins that reheating cannot destroy.

High-risk foods: cooked meat and poultry, dairy, eggs, shellfish, cooked rice, gravies, stocks, soft cheeses, prepared salads - high moisture, high protein, near-neutral pH.

Low-risk foods: dry goods (flour, rice, pasta), acidic foods (vinegar, citrus), high-sugar items (jam), and heavily salted products - poor microbial growth media.

Cross-contamination control rule: separate colour-coded boards, utensils and storage zones for raw and ready-to-eat; raw foods stored below cooked foods in refrigeration.

Deliberate contamination and sabotage are part of hazard analysis; access control, visitor sign-in and staff vetting reduce risk.

Infection vs intoxication: infection requires live cells multiplying in the gut (Salmonella, Campylobacter); intoxication is caused by pre-formed toxin in food (Staphylococcus aureus, Bacillus cereus).

Incubation periods guide investigation: S. aureus 1–6 h; B. cereus 1–6 h (emetic) or 8–16 h (diarrhoeal); Salmonella 12–72 h; E. coli O157 1–8 days; Listeria 1–70 days.

Campylobacter jejuni is the most commonly reported UK bacterial cause of gastroenteritis, linked to raw/undercooked poultry and cross-contamination.

Salmonella sources: raw eggs, poultry, meat, unpasteurised milk; symptoms include diarrhoea, fever and abdominal pain; infectious dose can be low in fatty foods (chocolate).

E. coli O157:H7 causes bloody diarrhoea and can lead to haemolytic uraemic syndrome (HUS), especially in children; very low infectious dose; linked to undercooked burgers and unpasteurised dairy.

Listeria monocytogenes grows at refrigeration temperature (down to about 0°C), survives freezing, and poses severe risk in pregnancy, the elderly and immunocompromised.

Clostridium perfringens: anaerobic spore-former; associated with cooked meats, stews and gravies cooled slowly; diarrhoea 8–22 h after eating.

Norovirus: viral, very low infectious dose, spread by infected food handlers, contaminated water/shellfish and surfaces; alcohol gels are less effective than soap and water.

Bacillus cereus: spore-former linked to cooked rice left at room temperature; reheating does not destroy the heat-stable emetic toxin.

Handwashing steps: wet hands, apply soap, lather and rub for at least 20 seconds including fingertips, thumbs, between fingers and wrists, rinse, dry with disposable towel.

Handwashing is required before starting work, after toilet use, after handling raw food, after breaks, after cleaning, after touching hair/face, and after handling waste.

Exclusion rule (UK): food handlers with vomiting and/or diarrhoea must be excluded until 48 hours after symptoms have ceased.

Reportable conditions to a manager: diarrhoea, vomiting, infected wounds, skin infections, sore throat with fever, jaundice, and any household contact with similar illness.

Food handlers must report if they or household members have typhoid, paratyphoid, E. coli O157, Shigella, hepatitis A or Norovirus.

Protective clothing: clean, light-coloured overalls, hair restraint, and waterproof plasters that are detectable (blue) covering any exposed wound.

Jewellery and nail rules: no rings (except a plain wedding band where permitted), no nail varnish, no false nails, no wristwatches on food-handling hands.

Eating, drinking, smoking and vaping are prohibited in food-handling areas; designated break areas only.

Return-to-work after exclusion may require medical clearance for certain pathogens (e.g. E. coli O157, typhoid) depending on local policy.

Bacterial growth curve phases: lag (adaptation), log/exponential (rapid multiplication), stationary (nutrients/space limited), decline (death).

Intrinsic factors controlling growth: pH, water activity (a_w), nutrient content, redox potential, antimicrobial compounds; extrinsic: temperature, atmosphere, competing flora.

Most pathogens are inhibited at pH below 4.6; a_w below 0.85 generally prevents bacterial growth (dry foods).

Chemical hazards: cleaning chemicals, sanitiser residues, pest control chemicals, lubricants, veterinary residues, mycotoxins, and allergens as chemical proteins.

Chemical control: never decant into unlabelled containers; store chemicals away from food; use food-grade lubricants; follow dilution rates and rinse where specified.

Physical hazards: glass, metal, stones, bone, plastic, wood, pests; control via supplier specifications, sieves/magnets, glass register, breakage procedure, and equipment maintenance.

The 14 regulated allergens (UK/EU) include celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, molluscs, mustard, nuts, peanuts, sesame, soybeans, sulphur dioxide/sulphites above 10 mg/kg.

Allergen controls: documented ingredient lists, supplier verification, segregation of allergen-containing ingredients, dedicated utensils, and cleaning to prevent cross-contact.

Allergen labelling: pre-packed food must emphasise allergens in the ingredients list; non-prepacked food must provide allergen information in writing or via a clear signpost to it.

Danger zone: 8°C to 63°C (UK guidance); bacteria multiply fastest around 37°C; minimise time in this range.

Refrigeration: chilled storage at 8°C or below (commonly 1–5°C); high-risk foods should be kept at 5°C or below where practicable.

Freezing: domestic/commercial freezers at -18°C or below; freezing stops multiplication but does not kill most bacteria.

Cooking rule: core temperature of 75°C for at least 30 seconds (or equivalent time/temperature combination) for poultry, minced meat products and reheated food.

Cooling rule: cool cooked food from 63°C to 8°C within 90 minutes (or from 63°C to 21°C within 90 minutes, then to 5°C within a further 90 minutes) where using a two-stage method.

Reheating: reheat to 82°C or above, or to 75°C for at least 30 seconds; reheat only once and never reheat food in a bain-marie.

Hot holding: hold at 63°C or above; cold holding at 8°C or below (5°C where practicable).

Probe use: clean and disinfect between uses; use a probe with a thin tip; take the temperature at the thickest part or centre.

Preservation methods: chilling, freezing, drying, salting, curing, smoking, pickling/acidification, canning/heat processing, modified atmosphere packaging, irradiation.

Cleaning removes visible dirt and food debris; disinfection reduces microorganisms to a safe level; sterilisation destroys all microorganisms - different terms, different purposes.

Two-stage cleaning: clean with detergent and hot water, rinse, then disinfect with a food-safe sanitiser at the manufacturer's contact time, then air-dry.

Contact time matters: sanitiser must remain wet on the surface for the stated time (often 30 seconds to 5 minutes depending on product).

Cleaning schedule (cleaning schedule / cleaning programme) should specify what, how often, with what chemical, at what dilution, and who is responsible.

Clean as you go: clean and disinfect surfaces and utensils between raw and ready-to-eat tasks, and at least every 4 hours in continuous high-risk operations.

Colour-coded cleaning equipment prevents cross-contamination between food areas, toilets and waste areas.

Waste: store in lidded, leak-proof containers; remove frequently; keep waste areas away from food storage and preparation; clean and disinfect bins.

Waste oil and grease must be collected by licensed contractors; documentation (waste transfer notes) retained.

Effective cleaning requires the right chemical concentration, temperature, contact time and mechanical action (the four factors of cleaning).

Pests of concern: rodents (rats, mice), insects (cockroaches, flies, ants, stored-product moths/beetles), birds, and domestic animals.

Signs of pest activity: droppings, gnaw marks, smear marks, footprints, live or dead insects, egg cases, nesting material, damage to packaging.

Proofing: fit door sweeps and bristle strips, mesh over vents and windows, seal gaps around pipes and cables, self-closing doors, and air curtains.

Premises design: smooth, impervious, washable surfaces; coving at wall-floor junctions; adequate lighting; drainage with traps; separate hand-wash basins with soap and towels.

Flow principle: design to separate clean and dirty flows, raw and cooked, and to move waste away from food preparation areas.

Pest control contractors should be licensed, provide written reports, and use bait stations sited away from food; baits must be secured and recorded.

Fly control: screens, UV fly-killers positioned away from food, and prompt waste removal; electric fly-killers must not be sited above food preparation surfaces.

Rodent control: proofing, hygiene, and monitoring; rodenticides require careful siting and documentation to prevent chemical contamination of food.

Domestic animals must be excluded from food rooms; assistance dogs may be permitted in customer areas only under controlled conditions.

HACCP principles (seven): hazard analysis; determine CCPs; establish critical limits; establish monitoring; establish corrective actions; establish verification procedures; establish record-keeping.

Prerequisite programmes (PRPs) underpin HACCP: cleaning, pest control, personal hygiene, training, supplier approval, maintenance and traceability.

Critical Control Point (CCP): a step where control can be applied and is essential to prevent, eliminate or reduce a food safety hazard to an acceptable level.

Critical limit: a measurable value (e.g. 75°C for 30 seconds, pH 4.6, a_w 0.85) that separates acceptable from unacceptable.

Monitoring: scheduled observation or measurement (e.g. probe temperature, sanitiser concentration) recorded with time, result, initials and corrective action.

Corrective action: what to do when a critical limit is breached - e.g. hold, reheat, reject, recall, retrain - and record it.

Verification vs validation: verification confirms the system is working (audits, records review, product testing); validation confirms the controls are scientifically capable of controlling the hazard.

Legal framework (UK): Food Safety Act 1990; Food Hygiene Regulations 2006 (EC 852/2004) require food business operators to put in place, implement and maintain permanent procedures based on HACCP principles.

Traceability: food business operators must be able to identify suppliers (one step back) and immediate customers (one step ahead); records retained for the required period.

Due diligence defence: documented HACCP records, training records, cleaning schedules and supplier approvals support a due diligence defence.