Turns black when the surface temperature reaches 160F as required by the 2017 FDA Food Code. Note that this measures the surface temperature, not the final rinse temperature. Features and Benefits Label changes from white to black when the surface temperature of the dish reaches the correct temperature. Keep labels for record keeping after removal. Dishwasher Temp Monitoring Ecolab Premium Dishwasher Temp Labels are designed to help you verify proper sanitation temperatures in your dishmachine, prepare meals, help you comply with food code requirements*, and keep your guests safe. Ecolab Premium Dishwasher Temp Labels Benefits: Plastic label with adhesive adheres to surface of pan or other item Label removes easily and leaves no residue Irreversible color change once temperature has been reached Accuracy +/-2ºF