Regulations Regarding the Use of Mercury-Filled Glass Thermometers in Professional Kitchens

In California, it is illegal to use mercury-filled glass thermometers in a professional kitchen. The California Uniform Retail Food Facility Law governs such practices, and the law is clear that mercury thermometers are not approved for use in commercial or public food preparation facilities. The reasoning behind this is the risk of contaminating food with mercury, which is poisonous, should the glass break. Glass thermometers that use alcohol to indicate the temperature may be used; however, the state recommends that restaurant and commercial kitchens use bimetallic stem probe thermometers (commonly called instant-read thermometers) or digital probe thermometers instead. With these, not only is the risk of mercury poisoning eliminated, there is no potential for broken glass and, in the case of thermocouple digital probe thermometers, because different probes are used for different types of food products, there is less risk of cross-contamination. If you are unsure as to whether a thermometer contains mercury or alcohol, note that the alcohol solution is generally tinted red or blue, whereas mercury is a dull silver-gray color. For the record, California state law does not prohibit the use of glass mixing bowls, measuring cups, or other glass tools or utensils in commercial kitchens, but these items are impractical and really have no place in a professional setting. Because state law, not federal, governs these practices, you should contact the proper authority to determine the regulations for the state you work in.