When do I need to sanitize my thermometer?

A food thermometer is a food-contact surface so it needs to be cleaned and sanitized in the same way that other food-contact surfaces are. Therefore, at the beginning of the day, wash the stem with soapy water, rinse under warm water, and sanitize. The stem can be sanitized by immersing in a properly prepared chemical sanitizing solution or by wiping off the stem with an alcohol swab. Most environmental health inspectors use the latter method to sanitize their thermometers.

If measuring the temperature of a raw food and then measuring the temperature of a cooked or ready-to-eat food, the stem must always be rewashed, rinsed, and then sanitized between uses. For example, if the thermometer is used to check the temperature of raw chicken and then used to check the temperature of tuna salad, it must be cleaned and sanitized before using with the tuna salad. However, if the thermometer is only used to check the temperature of properly cooked or ready-to-eat foods, such as tuna salad and cut melon, then it can simply be wiped cleaned with a clean paper towel and then immersed in a sanitizing solution or wiped with an alcohol swab.

If the thermometer is in continuous use for four hours, then it must be cleaned and sanitized regardless of what types of food it is being used to check.