EXPOSURE TIME TO RECEIVE A SEVERE BURN
|45°||113°||2 hours||3 hours|
|47°||116.6°||20 minutes||45 minutes|
|48°||118.4°||15 minutes||20 minutes|
|*49°||*120°||8 minutes||10 minutes|
|51°||124°||2 minutes||4.2 minutes|
|55°||131°||17 seconds||30 seconds|
|60°||140°||3 seconds||5 seconds|
*Activation temperature = 120° max
(response time is less than 5 seconds)The above table shows that a person will receive a second degree burn in 3 seconds of exposure and a third degree burn in 5 seconds of exposure to water of 140°F. A maximum temperature of 120°F at the discharge outlet will ensure the most safety for users.
The American Journal of Public Health prefers a maximum temperature of 120°F for hot water.
The Consumer Product Safety Commission and the plumbing industry have published a voluntary standard which states that the maximum allowable temperature at the water outlet to the bathing area should be 120°F.
There are national standards set forth by the major plumbing code making bodies, which specify a maximum temperature of 120°F for delivered hot water. The major code making bodies include:
Other nationally recognized plumbing code bodies that have published or proposed standards specifying 120°F as the maximum allowable discharge temperature include:
American Society for Testing & Materials (ASTM F444-88) Standard Consumer Safety Specification for Scald-Prevention Devices and Systems in Bathing Areas.
American Society of Sanitary Engineers and Plumbing Manufacturers' Institute(ASSE 1016) - Individual Thermostatic Pressure Balancing and Combination Control Valves for Bathing Facilities.
American Society of Sanitary Engineers and the Plumbing Manufacturers' Institute(ASSE 1062) - Temperature Actuated Flow Reducers for Individual Fixture Fittings. Passed the ASSE Standards Committee - April 26, 1996
Other organizations that specify a maximum of 120°F for delivered water temperature include:
Moritz AR Henriques FC Jr. Studies of thermal injury II:
The relative importance of time and surface temperature in the causation of cutaneous burns. Am J Pathol. 1947; 23: 915-941.
ALSO CHECK THE FOLLOWING SOURCES:
Purdue GF Hunt JL. Chapter 10: Burn injuries. pages 105-116. IN: Ludwig S Kornberg AE (editors). Child Abuse A Medical Reference Second Edition. Churchill Livingstone. 1992.
Rivara FP Grossman DC Cummings P. Injury Prevention. N Engl J Med. 1997; 337: 613-618.