Canadian Health Network

Send this to a friend Print-friendly version Scalds Past Articles Subscribe to our Healthlink newsletter

s your hot water at a safe temperature? Few people realize that hot water burns like fire. In most Canadian homes, hot water temperature is set at 60°C (140°F). At this temperature, human skin burns severely in just 1 to 6 seconds. The water at your hot water taps should be no hotter than 49°C (120°F). At this safer temperature, it takes at least 2 minutes to cause a severe burn, allowing more time to escape serious injury.

Each year, hundreds of Canadians are treated in hospitals for a tap water scald. Young children, elderly people, and people with disabilities are most vulnerable to these serious burns. This is because their skin is thinner, or they cannot react quickly to escape the hot water, or they lack skin sensitivity due to other medical conditions (such as diabetes), or a combination of these factors.

What if a 3-year-old boy climbs up to play at the sink? What if a 75-year-old woman falls into the tub while she is preparing her bath? If the hot water is 60°C, they have virtually no time to escape. For children, the aftermath of these burns is painful and emotionally traumatic. Ongoing assessment and possibly surgery may be required over many years in order to release the damaged skin as a child grows. Elderly victims are particularly vulnerable to complications. As a result, more than half of elderly people hospitalized for tap water scalds will die.

The good news is that hot water burns can be prevented. Research conducted in 1947 has shown that small reductions in temperature dramatically reduce the risk of burn injury from hot water. But turning this knowledge into action has been a slow process. While people can learn how to lower their water temperatures at home, it is more effective in the long run if we can make changes to building codes that govern the construction of homes and the standards that govern the design of hot water systems. In this way, safety can be "built in" to our homes.

Injury prevention organizations have been advocating for these changes for many years. A coalition of public health stakeholders proposed changes to the National Building and Plumbing Codes to require that hot water in new homes must be no hotter than 49°C at every tap. These model codes are typically adopted by the provinces and territories to govern new construction. The proposed changes have been through several steps in the approval process but have yet to be adopted nationally. Progress has been made in Ontario. Spearheaded by Safe Kids Canada's advocacy efforts, the Ontario Government introduced regulations to limit hot water temperature to taps in September 2004. In addition to advocating for improvements to building codes, Safe Kids Canada requested that several committees of the Canadian Standards Association consider improvements to standards for hot water heaters and plumbing devices which control water temperature.

To protect your family, you can apply one of these methods to ensure safe water temperature in your home.

• The thermostat of single-family hot water tank may be lowered. When lowering hot water tank temperatures, it is important to consider hot water availability and water quality. Gas and oil fired heaters may be lowered to 49°C. Due to the design of some electric hot water tanks lowering the temperature of water stored is not recommended.. If thermostats are adjusted to a higher temperature, tempering devices as described below are needed to protect your family.
• Devices, called mixing valves or tempering valves, can be installed in the plumbing lines or at the exit of the hot water tank. These devices ensure that water is delivered at 49°C by mixing in cooler water as needed.
• Devices, known as shut off or anti scald devices, can be installed at individual taps or faucets. If the water gets too hot, these devices slow the water to a trickle. You then restart the water by mixing more cold water into the tap. If you live in a multi-unit building and do not have access to your hot water tank, lowering your hot water temperature will probably require installation of tempering valves or anti-scald devices.

			Testing Hot Water Temperatures
			Remember to routinely check hot water temperature at the tap. Use a thermometer which can show high temperatures, like a meat or candy thermometer. Turn on the hot water tap in your bathroom. Let it run for 2 minutes. If you have used a lot of hot water in the past hour, wait 2 hours before you do this test. Fill a cup with the hot water. Put the thermometer in the cup. Look at the temperature. If it is higher than 49°C (120°F), you need to lower your water temperature.

Mixing valves or tempering valves,should always be installed by a professional. If you live in Ontario, you can contact your rental tank provider for options.

Parents and caregivers should always check the temperature of the water before bathing children and other vulnerable people. Ideal bath water temperature is around 37°C (98.6°F) for children. Supervision is critical to ensure safety around water.

Make sure your water temperature isn't too low either.

It is important to note that potentially harmful bacteria can grow in water heaters set too low. Do not lower the temperature of your household water heater below 49°C.

Of particular concern is the bacteria that causes Legionnaire's Disease. People with certain medical conditions should check with their doctors before reducing the temperature of the hot water tanks in their homes. These conditions include a weak immune system, lung and respiratory problems, or organ transplants. Most families, however, can safely reduce their hot tap water temperature. Check with your health care provider to be sure.

In multi-unit buildings served by complex water systems the hot water thermostat should remain high to ensure public health protection and a sufficient supply of hot water throughout the building. Scald protection can be achieved by installing the safety devices described above.

Further information on proposed new codes can also be obtained from the National Research Council Canada. You may contact them through their website, http://www.nationalcodes.ca/general_contact_e.shtml.

For more information on product standards visit the CSA.