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
- What is cross-contamination?+
- The transfer of harmful bacteria or allergens from one food, surface, person or piece of equipment to another.
- Can I use the same board for raw chicken and salad?+
- Only after washing and sanitising it (or using a separate clean board). Wiping is not enough.
- What is cross-contact?+
- The allergen version of cross-contamination — allergen traces transferring via shared equipment, hands or oil. Cooking does not remove allergens.
- How can I revise cross contamination quickly?+
- Use topic-drill mode for cross contamination and read the explanation on every question you miss, then re-test. Flashcards and a full 40-question practice test help the knowledge stick before your assessment.
See also: Cross Contamination: Exam Tips.
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