Matt Michel: Let's talk scalding

Scalding in the home or burns from hot liquids is dangerous to anyone, but is a particular concern to the youngest and oldest Americans. Plumbers are charged with protecting the health of the nation. Thus, plumbers can play a key role in reducing the risk, starting with homeowner education.

Scalding can happen fast

The speed of scalding increases with temperature. At 120° F, it takes five minutes for the typical adult to scald. Increase the water temperature another 20° and the time for a bad burn drops to five seconds.

In reality, five seconds is a long time. Count to five Mississippi. It’s hard to imagine leaving a hand under a tap or standing under a shower with scalding water for five long seconds. For children and the elderly, it is a different story.

The very young are at much greater risk to scalding. The time necessary to cause a burn takes only 25% as long for seniors and the very young.

The skin or dermal layers of the young is thinner. In addition, young children are less able to recognize what is happening and have less ability to react. According to the American Burn Association, 61% of scalds occur in children age five or younger.

Similarly, the elderly have thinner dermal layers. As people age, mobility and reaction time are lessened, leading to greater risk of scalding. Nevertheless, the scalding incidence rate is similar to other adults. However, the complications are greater, potentially leading to skilled nursing.

The scalding/Legionella trade-off

The simple solution is to lower the water temperature, and this is exactly what government agencies recommend. It is also what most codes specify. Yet, there is a downside. It creates the potential for Legionella to grow in water tanks when the temperature is less than 140° F. Legionella causes Legionnaire’s Disease, which is bad news.

This is the trade-off. Lower water temperature to reduce the risk of scalding and increase the risk of Legionella. Reduce the risk of Legionella and raise the risk of scalding.

Preventing scalding and Legionella

There are three simple ways to eliminate the trade-off. First, use a mixing valve with a storage water heater. Keep the water temperature in the tank at 140° F while reducing the supply temperature leaving the mixing valve to 120° F or lower.

As the protector of the health of the nation, it is up to plumbers to let people know about the risks of scalding and Legionella.

The second approach is to use point-of-use mixing valves for tubs, showers, and sinks. While more expensive than a single mixing valve for the entire house, it will allow adjustments to meet individual preferences. Water temperature can be reduced in children’s bathrooms, for example.

A third approach is to replace storage water heaters with tankless water heaters. This, of course, takes away the potential for Legionella in the storage tank and allow homeowners to set the water temperature at whatever temperature is desired.

Talking with customers

As the protector of the health of the nation, it is up to plumbers to let people know about the risks of scalding and Legionella. Where code prevents plumbers from setting the water temperature above 120° F, plumbers can show homeowners how to change the temperature.

When homeowners have young children or when homeowners are seniors, the subject of scalding should be broached. The service plumber on the scene can simply say something like, “When small children are in a home, we’re required to talk about scalding.”

It will help if the company prepares collateral literature on scalding to hand to homeowners. A scald chart should be included. Let homeowners know the risks, the trade-offs, and the solutions. Then, it is up to homeowners to ask more questions, take action, etc.