Microbiological, Chemical, Physical and Allergenic Hazards
What this domain tests
This domain asks you to match a hazard type to its control. The exam is practical: which control actually removes or reduces the risk, and which only appears to.
Microbiological controls
Bacteria need food, moisture, warmth, time and suitable pH. Control by temperature (chill quickly, cook thoroughly, hot-hold above 63°C), by time (limit time in 8–63°C), by moisture (drying, curing), by acidity (pickling), and by competition (fermentation). Spores survive cooking; Clostridium perfringens and B. cereus are controlled by rapid cooling, not by reheating alone.
Chemical controls
Store chemicals below and away from food, in original labelled containers. Never decant into drinks bottles. Use food-safe lubricants and sanitisers at correct dilution; too strong is a chemical hazard, too weak fails to disinfect. Keep pesticides, rodent bait and cleaning agents locked away and recorded.
Physical controls
Use detectable plasters, brittle-plastic policy, metal detection or visual checks where appropriate, and pest-proof packaging. Glass and hard plastic near open food should be avoided or controlled by breakage procedure.
Allergenic controls
The UK recognises 14 allergens: celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, molluscs, mustard, peanuts, sesame, soybeans, sulphur dioxide/sulphites, and tree nuts. Control is by accurate ingredient information, separation, dedicated equipment where practicable, clean-down between runs, and avoiding allergen cross-contact from hands, cloths, fryers and boards. "May contain" is not a substitute for controls.
Worked example
A café makes a peanut-free sandwich on the same board used for peanut butter. Wiping with a dry cloth does not remove peanut protein. The correct control is a separate clean board and knife, handwashing, and a documented clean-down; the server must not promise "peanut-free" unless controls support it.
Traps
- Believing cooking destroys allergens - most are heat-stable.
- Treating "gluten-free" as the same as "no cross-contact".
- Using sanitiser as a substitute for cleaning before disinfection.
- Missing sulphur dioxide as an allergen in dried fruit and wine.