Each year more than 430 very young children are seriously injured through scalding in hot baths. Research has shown that, unlike other household accidents, the number of scalding incidents is not falling and the government has decided to take action.
It has been considered necessary for hot water to be stored at temperatures of no less than 60°C. This is mainly to prevent the proliferation of micro-organisms but also to allow the use of more compact storage cylinders, which can help reduce energy costs.
However, hot water temperatures that kill bacteria such as legionella will cause scalding. Scalding occurs well below the boiling point of water. Temperatures above 45°C can cause serious injury very quickly. With water at 70°C, partial thickness injuries occur in well under 1 second, and full thickness burns in approximately 10 seconds.
The new generation of thermostatic mixing valves provides a solution by mixing hot water (stored at a temperature high enough to kill legionella) with cold water to ensure constant and safe outlet temperatures to prevent scalding.
The office of the deputy prime minister (ODPM) is looking at bringing tap water temperatures under the building regulations and, subject to the views of BRAC (Building Regulations Advisory Committee) and a full public consultation, it is proposed to amend the Building Regulations Part G by 2006.