When you use hot water to sanitize surfaces, take precautions with temperature to protect food safety. Water used as a sanitizer in mechanical washing machines should be cooler than 194˚F, with a final sanitizing rinse of at least 180˚F. Water in a stationary-rack, single-temperature machine should be at least 165˚F. Water used in the third compartment of a three-compartment sink should be at least 171˚F. Food safety research from the U.S. Department of Agriculture advises that cleaned items be exposed to these temperatures for at least 30 seconds to ensure they are properly sanitized.