FOODSAFE Cleaning and Sanitizing 1 — Questions and Answers
Question 1: What is the correct order for the three-compartment sink method of manual dishwashing?
- Sanitize, wash, rinse
- Rinse, sanitize, wash
- Wash in hot soapy water, rinse in clean water, sanitize in approved solution (Correct answer)
- Soak, rinse, air dry
Correct answer: Wash in hot soapy water, rinse in clean water, sanitize in approved solution
The three-compartment sink process is: 1) Wash in hot soapy water (minimum 44°C/110°F) to remove food and grease, 2) Rinse in clean water to remove soap, 3) Sanitize in approved chemical solution or hot water (77°C/170°F for 30 seconds).
Question 2: What is the minimum concentration of chlorine (bleach) solution typically used for sanitizing food-contact surfaces?
- 10 ppm
- 50 ppm at room temperature, or 100 ppm for immersion sanitizing (Correct answer)
- 200 ppm
- 500 ppm
Correct answer: 50 ppm at room temperature, or 100 ppm for immersion sanitizing
A chlorine solution of at least 50 ppm (parts per million) is used for wiping food-contact surfaces at room temperature, with a contact time of at least 45 seconds. For immersion sanitizing, 100 ppm is typically required.
Question 3: Why must surfaces be cleaned before being sanitized?
- Cleaning and sanitizing serve the same purpose, so order does not matter
- Organic matter and food residue shield bacteria from the sanitizing agent, making it ineffective on dirty surfaces (Correct answer)
- Sanitizing first makes cleaning easier
- Surfaces only need one step, not both
Correct answer: Organic matter and food residue shield bacteria from the sanitizing agent, making it ineffective on dirty surfaces
Food residue, grease, and organic matter create a physical barrier that prevents sanitizers from reaching bacteria on the surface. Cleaning first removes this barrier, allowing the sanitizer to make direct contact with microorganisms.
Question 4: What temperature should the water in the hot-water sanitizing method reach in a three-compartment sink?
- 50°C (122°F) for 2 minutes
- 77°C (170°F) for at least 30 seconds immersion (Correct answer)
- 100°C (212°F) for 10 seconds
- 60°C (140°F) for 1 minute
Correct answer: 77°C (170°F) for at least 30 seconds immersion
Hot water sanitizing requires water at 77°C (170°F) or higher with items immersed for at least 30 seconds. This temperature kills most vegetative bacteria. A thermometer or heat-sensitive tape should verify the temperature.
Question 5: How should sanitizer concentration be verified in a food service operation?
- By the colour of the solution
- By using chemical test strips designed for the specific sanitizer being used (Correct answer)
- By smelling the solution
- Verification is not necessary if the manufacturer's instructions are followed
Correct answer: By using chemical test strips designed for the specific sanitizer being used
Chemical test strips (test papers) specific to the sanitizer type (chlorine, quaternary ammonium, iodine) must be used to verify proper concentration. Visual inspection and smell are unreliable methods.
Question 6: What should be done with dishes and utensils after they have been sanitized?
- Dry them with a cloth towel immediately
- Allow them to air dry on a clean, sanitized rack (Correct answer)
- Stack them while still wet in a closed cupboard
- Rinse them with tap water to remove sanitizer residue
Correct answer: Allow them to air dry on a clean, sanitized rack
Air drying is the proper method after sanitizing. Towel drying can reintroduce bacteria from the towel. Rinsing removes the sanitizer before it has completed its work. Stacking wet items in closed spaces promotes bacterial growth.
FOODSAFE Cleaning and Sanitizing 1
What is the correct order for the three-compartment sink method of manual dishwashing?