Cross Contamination

Cross contamination is the transfer of harmful bacteria or allergens from one food, surface, person or piece of equipment to another. It is why raw chicken and salad must never share an unwashed board.

Separation plus cleaning and sanitising between tasks is the core defence.

Direct vs indirect

Direct: raw food touches ready-to-eat food (e.g. raw meat dripping onto a salad). Indirect: bacteria travel via hands, knives, boards or cloths. Store ready-to-eat food above raw, with raw poultry and mince at the bottom.

Bacterial vs allergen

Bacterial cross-contamination spreads pathogens (often killed by cooking); allergen cross-contact spreads allergen proteins, which cooking does not destroy. Use clean or dedicated equipment for allergic customers.

How to revise cross contamination for the exam

Practise the raw-to-ready-to-eat scenarios and remember gloves are not a substitute for hand washing. The questions are usually scenario-based, so practise applying the rule rather than just reciting it. Work through the Cross Contamination drill below until you can answer without hesitating, review anything you get wrong, then sit a full timed test to confirm you are exam-ready.

Common exam traps

  • Gloves are not enough — reused gloves spread bacteria; change them.
  • Wiping a board with a cloth is not cleaning — wash and sanitise it.
  • Shared fryer oil carries the wheat allergen to 'plain' chips.

Cross Contamination FAQ

See also: Cross Contamination: Exam Tips.

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