CIPHE | Advice on bathing danger
The Chartered Institute of Plumbing and Heating Engineering (CIPHE) is urging plumbing and heating professionals to help educate consumers about the dangers of hot water.
It’s in response to the inquest into the tragic accidental death of 18 month old Katelyn Seers who suffered burns after climbing into a hot bath. The tragedy occurred in 2007 after the toddler was left briefly unattended next to a bath that was filling up. She suffered 30% burns and died in hospital several days later from septic shock.
Danny Davis, principal technical officer at the CIPHE spoke about the Institute’s determination to help prevent similar accidents by encouraging members to raise awareness amongst their customers about controlling water temperature.
He commented, “It’s a tragic story but sadly there have been other similar cases, particularly involving disabled people and children who need extra care when bathing. Plumbing and heating professionals, who work in households with elderly or disabled people, or children, should tell the main care-giver about safe bathing temperatures and how a thermostatic mixing valve (TMV) can help. TMVs can limit the water temperature to the desired temperature so there’s no need for a separate thermometer and no need to worry.
”Since 2010 there has been a legal requirement in England and Wales (Scotland since 2006) to limit bathing outlet temperatures in new dwellings to 48⁰C. The British Burns Association recommends bathing temperatures for children should be 37-37.5⁰C.
Added Danny, “By educating the public and encouraging the use of TMVs we can help guard against future tragedies. It’s my sincere hope that what happened to Katelyn is never repeated. ”
CIPHE Databyte | Guidance on Preventing Domestic Hot Water Scalding
Every year around 20 people in the UK die as aresult of scalds caused by hot bath water, and afurther 570 suffer serious scald injuries that canresult in long-term disability and disfigurement. The young and the old are most at risk because their skin is thinner and less tolerant to highwater temperatures.
Recommended Use Although there is no legal requirement* to limit waterdelivery temperatures, DEFRA recommend the useof thermostatic mixing valves (TMVs) for terminalfittings in schools, public buildings and other facilitiesused by the public. In addition, the HousingCorporation recommends thermostatically controlledsupplies to bath taps in all housing. Thermostaticcontrol of showers and all hot water taps isconsidered essential in housing for the elderly.
TMV2 Valves Valves are now available that have been Certified tothe new BuildCert TMV2 scheme. These valves alsomaintain the pre-set temperatures even if the waterpressure varies when other appliances are used.They are generally made to a different Standard fromthe TMV3 valves that are made to NHSspecifications. The TMV2 valves require less frequentinspection or servicing than the TMV3 valves; makingthem more appropriate to domestic installations.
Maximum Outlet Temperatures The BuildCert TMV scheme recommends thefollowing maximum hot water temperatures for usein all premises:
• 46C for bath fill (please note this is not a safebathing temperature)
• 41C for showers.
• 41C for washbasins
• 38C for bidets
Temperatures should never exceed 46C
CIPHE Databyte | Safe Hot Water Temperature
Duty of Care
Legislation dictates recommendations and guidelines on health and safety, including safe hotwater temperatures. The emphasis is on regulatory and design criteria, with responsibility for meeting such guidelines being that of a suitably appointed responsible person.
The purpose of the responsible person is to ensure safe goods, services and working practices, by carrying out risk assessment to maintain the safety of employees, residents, tenants and members of the public. If a user, employee, etc is injured, the owner/manager (responsible person) can be prosecuted for breach of statutory obligations and failing to fulfil their duty of care.
Two factors which are relevant to safe hot water temperatures are: Legionella and Scalding
These two, apparently conflicting factors need to be taken into consideration by designers and installers of hot water systems to be used by vulnerable people such as children and the elderly.
Firstly the temperature of the hot water system needs to be high enough to stop naturally occurring Legionella multiplying to a level that will cause health problems.
Secondly, the NHS Estates specification recommends the maximum outlet temperatures for appliances to prevent scalding. These two factors mean that temperature control must be exercised throughout the system and at point of use.
How water temperatures affect Legionella
70°C to 80°C Disinfection range
66°C Legionella die within 2 minutes
55°C Legionella die within 5 to 6 hours
20°C to 45°C Legionella multiply
20°C & below Legionella are dormant
How water temperatures affect the skin
65°C a partial thickness burn in about 2 seconds
60°C a partial thickness burn in about 5 seconds
55°C a partial thickness burn in about 15 seconds
50°C a partial thickness burn in about 90 seconds
As water must be stored hot enough to eliminate Legionella, yet be cool enough to prevent scalding, point of use thermostatic mixing valves are one solution to the problem.
Maximum outlet Temperature requirements
Supervised Bath 46°C
Please Note HSE Document L8 states that water supply to the outlet should be at least 50°C within 1 minute after fully opening the outlet. However, Water Regulations guidance states that the required flow of water should reach the terminal fittings to sanitary and other appliances at a temperature of not less than 50°C within 30 seconds after fully opening the tap. However, realistically this criteria may not be achievable where hot water is provided by instantaneous water heaters or combination boilers.
Further sources of information include
NHS: Specification D 08
HSE Document L8
The Chartered Institute of Plumbing & HeatingEngineering cannot accept responsibility for any errors or omissions contained in this information.
CIPHE Student Study Section | A brief introduction to Thermostatic Mixing Valves