Which of the following is NOT an approved sanitizer for food service?

The choice indicating that water below 171°F is not an approved sanitizer for food service is correct because effective sanitization requires water to be at a temperature that allows for the proper kill rate of pathogens. For example, water that is heated to at least 171°F (or 77°C) serves as an effective sanitizer, primarily for surfaces and utensils, as high temperatures can denature proteins and deactivate many types of bacteria.

In contrast, chlorine, iodine, and quaternary ammonia are recognized as effective chemical sanitizers used in food service environments when used in proper concentrations. These sanitizers have been demonstrated to kill a wide range of pathogens when applied according to the manufacturer's instructions, making them suitable for ensuring food safety in restaurants and food establishments.