WSQ Cross-Contamination Prevention 2

Question 1

What is the correct way to prevent cross-contamination when wiping down surfaces in a kitchen?

Accepted Answer

Use designated colour-coded or separate cloths for different surfaces, change and sanitise cloths frequently, and use disposable paper towels where possible

Answer

Using the same cloth across multiple surfaces spreads contamination from one area to another. Best practice requires using separate, colour-coded cloths for different areas (e.g., food contact surfaces vs. non-food surfaces), sanitising cloths frequently, and preferring single-use paper towels for food contact surfaces.

Question 2

How should cleaning chemicals be stored in a food establishment to prevent contamination?

Accepted Answer

In a clearly labelled, separate, locked storage area away from food, food preparation areas, and food contact equipment

Answer

Cleaning chemicals, sanitisers, and pest control products must be stored in a separate, clearly labelled, and ideally locked area completely away from food, food preparation areas, and food contact surfaces. Chemical contamination can cause serious illness and is a major food safety hazard.

Question 3

What is the risk of using the same cooking oil repeatedly over many cycles without changing it?

Accepted Answer

The oil degrades, producing harmful compounds such as acrylamide and polar compounds that can contaminate food and pose health risks

Answer

Repeatedly using cooking oil at high temperatures causes degradation, producing harmful polar compounds and acrylamide (a probable carcinogen). Singapore's SFA has guidelines on oil degradation limits, and food establishments should change oil regularly and monitor oil quality using test kits.

Question 4

Why must raw seafood be stored separately from other foods in a refrigerator?

Accepted Answer

Raw seafood can harbour pathogens like Vibrio and Salmonella, and their juices can drip onto and contaminate other foods

Answer

Raw seafood commonly carries pathogens including Vibrio vulnificus, Vibrio parahaemolyticus, and Salmonella. Storing raw seafood above or near other foods risks drip contamination. It should be stored in sealed containers on the lowest shelves, separate from cooked and ready-to-eat foods.

Question 5

What is 'environmental contamination' as a source of cross-contamination in food preparation?

Accepted Answer

Contamination originating from the kitchen environment itself — including unclean surfaces, equipment, air, pest droppings, and contaminated water — transferring to food

Answer

The kitchen environment itself can be a source of contamination — unclean floors, walls, and surfaces harbour bacteria; pest droppings contaminate surfaces; contaminated water spreads pathogens; and dust or condensation can transfer contaminants to food. Environmental hygiene is a prerequisite for food safety.

WSQ Food Safety Practice Test

WSQ Food Safety Practice Test

WSQ Cross-Contamination Prevention 2