Food Safety Hazards and Contamination
A hazard is anything in food that could cause harm to the consumer. Candidates must be able to sort hazards into four families and give an example of each: biological (bacteria such as Salmonella, viruses such as norovirus, parasites, moulds), chemical (cleaning chemicals, pesticides, allergens, mycotoxins), physical (glass, metal fragments, plasters, pests) and allergenic (often taught separately because the harm is an immune reaction rather than poisoning).
Understand the difference between contamination (the presence of a hazard) and cross-contamination (hazard transferred from a source to a ready-to-eat food, directly or via hands, equipment, cloths, drip or pests). The four routes to remember are hands, surfaces/equipment, raw-to-cooked transfer, and pests or the environment.
Traps in questions: allergens are frequently miscategorised as chemical hazards when the syllabus treats them as their own category; a plaster in a sandwich is physical, not biological; and 'cross-contamination' is not the same as 'contamination'. Watch for questions asking which hazard is most likely in a given scenario rather than which is possible.
Rule of thumb: colour-coded boards and separate raw/cooked areas exist to break the raw-to-ready-to-eat route. If raw and ready-to-eat food share a surface, hands, or a knife, you have created a cross-contamination risk regardless of how clean the food looks.