With the average water heater settings, it only takes five seconds to cause a third degree burn.
Most home water heaters are set at 140°F to provide sufficient hot water and prevent the growth of Legionella and other harmful bacteria. At this temperature it only takes five seconds to cause a third degree burn. Children and the elderly have a thinner outer skin, so it takes half as long as adults to cause serious injury.
“Each year, approximately 3,800 injuries and 34 deaths occur in the home due to scalding from excessively hot tap water. The majority of these accidents involve the elderly and children under the age of five.”
– U.S. Consumer Product Safety Commission
Fortunately, tap water scalding accidents are 100% preventable! When you have a thermostatic mixing valve installed in your home, you can maintain water temperatures sufficiently high to prevent Legionella, and also limit tap and bath water temperatures to prevent scalding.
| Water Temperature | Time Needed to Cause 3rd Degree Burns |
|---|---|
| 155°F | 1 Second |
| 148°F | 2 Seconds |
| 140°F | 5 Seconds |
| 133°F | 15 Seconds |
| 127°F | 60 Seconds |
| 124°F | 3 Minutes |
| 120°F | 5 Minutes |
Source: Moritz, A.R., Herriques, F.C. Jr. Studies of thermal injuries: II The relative importance of time and surface temperature in the causation of cutaneous burns. Am J Pathol 1947; 23:695-720.
© 2006 Service Roundtable