Cross-Contamination Prevention and Cleaning and Sanitizing
What the exam tests
Questions focus on how contamination moves, the difference between cleaning and sanitising, and correct chemical use.
Breaking the chain
Cross-contamination occurs when microorganisms or allergens move from raw food, hands, equipment, cloths, drains or packaging to ready-to-eat food. Controls include separating raw and cooked/ready-to-eat areas and storage; using colour-coded boards and utensils; never using the same cloth for raw and ready-to-eat surfaces; washing hands and changing gloves between tasks; covering food and storing raw below cooked; and separating allergen-containing ingredients with dedicated scoops.
Cleaning and sanitising
Cleaning removes soil; sanitising reduces microorganisms to a safe level. The five steps are: scrape/remove debris, wash with detergent, rinse, apply sanitiser at the labelled concentration and contact time, then air-dry. Food-contact surfaces must be cleaned and sanitised after each task and at least every four hours during continuous use. Test sanitiser strength with strips; too strong can be toxic or corrosive, too weak is ineffective. Never towel-dry food-contact surfaces after sanitising.
Worked example
A worker cuts raw chicken, rinses the board with water, then slices salad. The board looks clean but is contaminated. Rinsing does not remove the fat/protein film or kill bacteria. The board must be washed with detergent, rinsed, sanitised at the correct concentration and contact time, and air-dried before ready-to-eat use - or a separate colour-coded board used.
Traps that cost marks
- Sanitising a visibly dirty surface: soil inactivates sanitiser.
- Assuming a hot water rinse equals sanitising.
- Using the same wiping cloth all shift.
- Storing clean equipment wet, stacked and without airflow.