Every year in Britain, approximately 20 people die and 600 suffer serious injuries resulting from contact with hot bath water.

Comfort and safetyFive seconds! That's all it takes to scald a child with bath at 6O°C. It's a common hazard: at least one child under the age of five is taken to an A&E department suffering from serious scald injuries as a result of extremely hot bath water. In fact, the problem is so prevalent that charities like CAPT (Child Accident Prevention Trust) and the Children's Fire and Burns Trust exist primarily to raise awareness of the potential dangers.

A casual observer of the problem would probably offer a simple solution - why not reduce the temperature at which we store hot water? However, lowering the stored temperature increases the risk of legionella - a naturally occurring organism that can cause Legionnaire's Disease.

Hot bath water kills! With due care and the latest water safety technology, we can significantly reduce accidents and the burden on over-stretched emergency services.

• The bacteria grow and multiply between 20 and 45oC.
• At less than 20oC the bacteria remains a potential threat.
• Temperatures above 65oC eliminate the risk.
  

Hot water temperatures that are unable to cause scalding are ideal for the propagation of legionella. High temperatures that eliminate the risk can cause scalding.

Legionnaire's Disease

There are around 200-250 recorded cases of Legionnaire's Disease in the UK each year.
Some 50% of these cases are associated with overseas travel.
Legionnaire's Disease is normally contracted by inhalation.

Main areas of risk include:

• Water system incorporating a cooling tower or evaporating condenser.
• Hot and cold water systems.
• Other water systems containing water above 20oC that may release water or aerosol droplets.
  

These can include humidifiers, spa baths, indoor fountains, water features and car washes.

The HSE Approved Code of Practice advice includes:

• Maintaining good hygiene in the water system
• Storing hot water above 60oC.

It also provides guidance on other water treatments, such as biocides, chlorine dioxide, ionisation and the use of oxone and UV. For more information see HSE Approved Code of Practice & Guidance Document L8.
Safe HOT Water Temperature Control

For over 25 years, thermostatic mixing valves (TMVs) have been used to blend hot and cold water to deliver safe, blended, hot water temperature for baths, basins and other points of use.

Thermostatic Shower valves are now installed as standard fittings in most new homes. They offer householders improved comfort and inherent safety, irrespective of variations in water system pressures.

The introduction by NHS Estates' Model Engineering Specification and the TMV3 Scheme (through BuildCert) ensures that TMVs installed in the high-risk sector deliver precise temperature control (preventing scalding) and are safer and easier to maintain.

For lower risk applications, such as in housing association installations, manufacturers introduced a new TMV2 Scheme, also administered by BuildCert.

Both schemes guarantee that products are independently tested and certified to conform with a rigorous set of performance and endurance criteria.

For guidance on product suitability, see the BRE / DTI document IP14/03 'Preventing Hot Water Scaldings in Bathrooms'.

Applications Guide

• TMV 2 - Domestic users, housing associations, hotels.
• TMV 3 - High Risk environments, hospitals, nursing homes.

During May 2006, Scotland's building regulations legislation was amended.

It required developers and contractors of all new homes to incorporate a thermostatic control to prevent scalding and provide safe hot bathing water (maximum temperature of 48oC).

Prominent charities, such as the Children's Fire and Burns Trust, gave their full support to Mary Creagh MP in her campaign to provide similar regulations in England.

Douglas Delabie is a founder member of the TMVA (Thermostatic Mixing Valve Manufacturers' Association).

The TMVA's main aims concern the safe provision of hot water at point-of-use:

• Raising awareness of the dangers of scalding.
• Promoting awareness of TMV benefits in preventing potential scalding.
• Creating a forum for leading manufacturers to engender continuous product/application development to improve safety.

Further information is available from:

• Thermostatic Mixing Valve Manufacturers' Association (TMVA) www.tmva.org.uk
• Children's Fire and Burn Trust www.childrensfireandburntrust.org.uk
• Child Accident Prevention Trust (CAPT) www.capt.org.uk
• BuildCert www.buildcert.com