Food Contamination Hazards and Their Prevention
Contamination is the presence of anything harmful in food. Candidates must classify hazards into biological (bacteria, viruses, parasites, moulds), chemical (cleaning chemicals, pesticides, allergens, veterinary residues, toxic metals), physical (glass, metal, plastic, stones, hair, pests) and allergenic, which is often treated as a separate category because it triggers immune reactions rather than infection. Understanding routes of contamination is essential: hands, equipment, surfaces, cloths, pests, air, water, raw food drip and packaging can all transfer hazards to ready-to-eat food.
The central control concept is separation. Raw and ready-to-eat foods must be separated by time, space or physical barriers; colour-coded equipment and boards help. Traps in questions include assuming that cooking fixes everything: cooking kills many biological hazards but does nothing for chemical or physical contamination, and it does not remove allergens. Another trap is the wiping cloth, which spreads contamination across surfaces if it is not changed and laundered frequently. Also expect questions on allergen cross-contact, where the hazard is a trace of an allergen rather than a pathogen, and where cleaning and dedicated equipment are the main controls.
A useful rule of thumb: for any contamination scenario, identify the hazard type, the route, and the control that breaks the route. For example, a glass jar breaks near a preparation bench: stop work, isolate the area, remove the broken glass, discard exposed food, clean and inspect, and record the incident.