Specifications

Safety

Dening Hot Water

Hot water can be dened in many ways. The most

common way to dene hot water is by the applicaon.

Water temperature that is considered hot for one

applicaon may be only warm in a dierent applicaon

and vice versa.

The following chart shows common temperatures used for

various applicaons. Two of the most common

temperatures used for residenal applicaons are 105°F

for showers and baths and 120-140°F for laundry

Commercial applicaons oen use much higher

temperatures than residenal applicaons. For example,

when using hot water for sanizing dishes, the Naonal

Sanitaon Foundaon (NSF) requires that water be 180°F

Although hot water is dened by its applicaon, it is

important to remember that with higher water

temperatures comes an increased risk of a scalding injury.

Water that is 120°F takes more than 5 minutes to cause a

scald injury. Water that is 160°F can scald in less than one

second. Small children, elderly people and the disabled are

most at risk of scalding injuries. Hot water to general use

xtures, such as lavatories, showers and bathtubs, should

be limited to 120°F or less. If water of a higher

temperature is required for some applicaons, a mixing

valve should be installed. The mixing valve, or tempering

valve, mixes cold water with the hot water supplied to

general use xtures lowering the temperature to within

safe limits.

Hot water can produce rst-degree burns within:

120°F (49°C) – more than 5 minutes

130°F (54°C) – in 20 seconds

140°F (60°C) – in 3 seconds

150°F (66°C) – in 1½ seconds

160°F (71°C) – in less than 1 second