Ontario Food Handler Certificate Cross-Contamination Prevention 1 — Questions and Answers
Question 1: What is cross-contamination in a food service environment?
- Cooking food at the wrong temperature
- The transfer of harmful substances or microorganisms from one food or surface to another (Correct answer)
- Serving expired food to customers
- Using too much seasoning in food preparation
Correct answer: The transfer of harmful substances or microorganisms from one food or surface to another
Cross-contamination is the transfer of harmful bacteria, allergens, or other contaminants from one food, surface, or object to another. It is one of the leading causes of food-borne illness.
Question 2: Which of the following is an example of direct cross-contamination?
- A food handler sneezing on food
- Raw chicken juices dripping onto ready-to-eat salad in the refrigerator (Correct answer)
- Using expired ingredients
- Cooking food on a dirty grill
Correct answer: Raw chicken juices dripping onto ready-to-eat salad in the refrigerator
Direct cross-contamination occurs when raw food or its juices come into direct contact with ready-to-eat food. Raw chicken dripping onto salad transfers Salmonella directly to the ready-to-eat food.
Question 3: Where should raw meat be stored in a refrigerator relative to ready-to-eat foods?
- On the top shelf above ready-to-eat foods
- On the bottom shelf below ready-to-eat foods (Correct answer)
- On the same shelf if in sealed containers
- In a separate refrigerator only
Correct answer: On the bottom shelf below ready-to-eat foods
Raw meat must be stored on the bottom shelf to prevent juices from dripping onto ready-to-eat foods below. Ready-to-eat foods should always be stored above raw products.
Question 4: What is the proper order for storing foods in a refrigerator from top to bottom?
- Raw poultry, raw ground meat, raw whole meat, ready-to-eat foods
- Ready-to-eat foods, seafood/whole cuts of meat, ground meats, raw poultry (Correct answer)
- Raw poultry, ready-to-eat foods, ground meats, seafood
- Any order is acceptable if foods are covered
Correct answer: Ready-to-eat foods, seafood/whole cuts of meat, ground meats, raw poultry
From top to bottom: ready-to-eat foods, then seafood and whole cuts of meat, then ground meats, and raw poultry on the bottom. This order is based on required cooking temperatures, with the highest risk at the bottom.
Question 5: A food handler uses the same cutting board to cut raw chicken and then slice tomatoes for a sandwich. What type of contamination has occurred?
- Chemical contamination
- Physical contamination
- Indirect cross-contamination through a shared surface (Correct answer)
- No contamination has occurred
Correct answer: Indirect cross-contamination through a shared surface
This is indirect cross-contamination — bacteria from the raw chicken transferred to the cutting board, and then to the tomatoes. The cutting board served as the vehicle for contamination.
Question 6: Which of the following is the BEST practice for preventing cross-contamination with cutting boards?
- Use one cutting board for everything and wash it between uses
- Use separate color-coded cutting boards for raw meats, vegetables, and ready-to-eat foods (Correct answer)
- Only use wooden cutting boards as they are naturally antibacterial
- Flip the cutting board over between different foods
Correct answer: Use separate color-coded cutting boards for raw meats, vegetables, and ready-to-eat foods
Color-coded cutting boards dedicated to specific food types (e.g., red for raw meat, green for vegetables) prevent cross-contamination by ensuring raw meat surfaces never contact ready-to-eat foods.
