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

In food service environments, sanitizers are crucial for preventing foodborne illnesses by effectively eliminating pathogens on food contact surfaces. While chlorine, iodine, and quaternary ammonia are widely recognized and approved sanitizers used in various food service applications, hydrogen peroxide does not typically fit within the category of approved sanitizers for direct food contact surfaces.

Hydrogen peroxide is a strong oxidizer and can be effective as a disinfectant in some contexts, but its use as a sanitizer in food service is limited. This is primarily due to its potential to leave behind residues and its less established efficacy on food contact surfaces compared to the other options listed. Additionally, sanitizers like chlorine, iodine, and quaternary ammonia have established guidelines for their concentrations and contact times, making them safer and more reliable choices in food service settings.

Therefore, hydrogen peroxide is not commonly used or recognized as an approved sanitizer in the same way the others are, making it the correct answer to the question.