Hot water delivered at 60°C, a typical thermostat setting for storage-type service water heaters, will severely burn human skin in 1 to 5 s. Consequently, Article 7.2.10.7. sets an upper limit on the temperature of water discharging from shower heads and into bathtubs. The water temperature is maintained at or below this limit through the installation and adjustment of automatic compensating valves or temperature-limiting devices. Compliance with the Article reduces the risk of scalding in showers and bathtubs, which could result in severe burns, and the risk of thermal shock in showers, which could lead to falls.
Children, older adults and people with disabilities are particularly at risk of scalding because they are not always able to remove themselves quickly from a shower or bathtub if the water becomes too hot.
At a water temperature of 49°C, the time for a scald burn to occur on is nearly10 min, whereas the time for a scald burn to occur on an older adult is only 2 min because their skin is thinner and less vascularized. At a water temperature of 43°C, scald burns occur only after several hours of exposure. Therefore, setting 43°C as the maximum temperature for water discharging from shower heads and into bathtubs provides suitable protection from scald burns in healthcare facilities and seniors’ residences.
Although the temperature of water discharging into other fixtures, such as lavatories, sinks, laundry trays and bidets, is not addressed by Article 7.2.10.7., a risk of scalding may nonetheless exist at such fixtures.
It should be noted that pressure-balanced valves are sensitive to seasonal changes in the temperature of the cold water supply and may require adjustments throughout the year to avoid exceeding the maximum water temperature prescribed in Article 7.2.10.7.