TFM Cross-Contamination Prevention 2 — Questions and Answers
Question 1: What is the difference between cleaning and sanitizing?
- They are the same process
- Cleaning removes dirt and food; sanitizing reduces pathogens to safe levels (Correct answer)
- Sanitizing removes dirt; cleaning kills bacteria
- Cleaning uses chemicals; sanitizing uses water only
Correct answer: Cleaning removes dirt and food; sanitizing reduces pathogens to safe levels
Cleaning removes visible dirt and food debris, while sanitizing uses heat or chemicals to reduce microorganisms to safe levels — both steps are required.
Question 2: What must be done to a food contact surface before sanitizing?
- Apply the sanitizer directly to the dirty surface
- Clean the surface with soap and water and rinse first (Correct answer)
- Dry the surface completely
- Heat the surface with a heat gun
Correct answer: Clean the surface with soap and water and rinse first
Surfaces must be cleaned and rinsed before sanitizing because food debris and soap residue can inactivate chemical sanitizers.
Question 3: A chef uses the same tongs to handle raw shrimp and then places cooked shrimp on a serving platter. This is an example of:
- Proper time-temperature control
- Direct cross-contamination (Correct answer)
- Physical contamination
- Chemical contamination
Correct answer: Direct cross-contamination
Using unwashed tongs from raw to cooked shrimp directly transfers pathogens from the raw food to the ready-to-eat food, causing direct cross-contamination.
Question 4: What is the purpose of using separate equipment for raw proteins versus ready-to-eat foods?
- To meet aesthetic standards in the kitchen
- To prevent pathogens from raw foods contaminating foods that won't be cooked (Correct answer)
- To speed up kitchen operations
- To reduce dishwashing time
Correct answer: To prevent pathogens from raw foods contaminating foods that won't be cooked
Dedicated equipment for raw proteins prevents their pathogens from transferring to ready-to-eat foods that have no further cooking step to eliminate contamination.
Question 5: Which of the following scenarios represents chemical cross-contamination?
- Raw chicken juices dripping onto lettuce
- Cleaning chemical residue left on a cutting board used for food prep (Correct answer)
- A food handler sneezing on a salad
- Hair falling into soup from an uncovered head
Correct answer: Cleaning chemical residue left on a cutting board used for food prep
Chemical cross-contamination occurs when cleaning or sanitizing chemicals are transferred to food or food contact surfaces, contaminating the food.
Question 6: When should a sanitizer solution's concentration be tested?
- Once at the beginning of the day only
- Regularly throughout the day using a test kit or strips (Correct answer)
- Only when it appears cloudy or discolored
- Every 4 hours regardless of use
Correct answer: Regularly throughout the day using a test kit or strips
Sanitizer concentrations should be regularly tested with appropriate test strips or a kit because concentration decreases with use and dilution.
TFM Cross-Contamination Prevention 2
What is the difference between cleaning and sanitizing?