Quick answer: A high-temperature commercial dishwasher washes at 150 to 165°F and runs a final sanitizing rinse of 180°F, hot enough to bring the dish surface to 160°F. A low-temperature machine sanitizes with a chemical in the final rinse instead of heat. The Food Code sets a floor rather than a range: under Section 4-501.110(B), the wash solution in a chemical-sanitizing machine may not be less than 120°F. Check the data plate, because your machine’s own spec may be higher.
There is no single number, because commercial dish machines sanitize one of two ways. High-temperature machines use heat, so they run hot and finish with a scalding rinse. Low-temperature machines use a chemical sanitizer, so they run cooler and rely on the chemical, not the heat, to kill pathogens. The FDA Food Code and the NSF standard behind your machine’s data plate set these targets, and that data plate lists the exact temperatures your unit is built to hit.
High-temperature (heat sanitizing) machines
- Wash: 150 to 165°F, depending on the machine type (a stationary-rack, single-temperature machine runs the hottest wash at 165°F).
- Final sanitizing rinse: 180°F at the manifold (a stationary-rack, single-temperature machine is the exception, sanitizing at 165°F).
- Dish surface: the rinse has to be hot enough to bring the plate’s own surface to 160°F, which is what actually sanitizes it. Check it with a heat-sensitive test strip run through on a dish.
High-temp machines need a booster heater to reach 180°F, and the rinse should not climb past about 194°F, where water starts flashing to vapor and sanitizes less effectively.
Low-temperature (chemical sanitizing) machines
These sanitize with a chemical dosed into the final rinse rather than with heat. The Food Code requires the wash solution to be at least 120°F (Section 4-501.110(B)) and sets no upper limit, so check your machine’s data plate for its own spec. The temperature is not doing the sanitizing, so the chemical concentration is what you verify, with test strips, every day:
- Chlorine: 50 to 100 ppm
- Quaternary (quat): 150 to 400 ppm
- Iodine: 12.5 to 25 ppm
Oversize items and the three-compartment sink
Anything too big for the machine, like sheet pans, gets washed by hand in a three-compartment sink: wash in hot soapy water at 110°F or hotter, rinse, then sanitize. Heat sanitizing in the sink means immersing items in 171°F water, hot enough to burn, so most kitchens sanitize the third sink with a chemical instead.
Why the number matters to an inspector
Warewashing temperature is one of the first things a health inspector checks, because a machine that cannot reach temperature is running an unsafe wash even when the dishes look spotless. Inspectors look at the gauge, at a test strip pulled off a real cycle, and at whether staff can say which method the machine uses. If sanitizing cannot be proven, the wash does not count.
A dish machine that will not reach 180°F, or hold its sanitizer strength, is a failed inspection waiting to happen, and it is usually a booster heater, a thermostat, or a chemical-feed problem. ProToCall repairs and maintains commercial dishwashers and warewashing equipment. Call 866-297-5082 or schedule restaurant equipment repair and maintenance.