Managing the risk of scalding and controlling for Legionella
When installing taps in the healthcare sector, the overriding concern is for user safety. The Health & Safety Executive (HSE) guidance for Legionella control recommends the production and distribution of hot water above 60°C. However, this increases the risk of scalding. Centralised thermostatic mixing valves, certified to D08 performance specification, are regularly installed to ensure compliance. These deliver mixed water at a safe temperature and include a hot and cold water failsafe if the water supply fails. However, they are installed behind panels and are difficult to access for servicing. Since water is pre-blended, cold water draw-off at the point-of-use is reduced, resulting in a dead leg. If the water is not purged regularly, the risk of Legionella contamination is increased.
Patient safety a priority
Phil Mitchell, Environmental Estates Officer at the John Radcliff hospital in Oxford takes a completely different approach to reducing the scalding risk. Patient safety is still a major concern but Phil has taken time to understand the application for each point-of-use, identified the scalding risk, and installed tapware fit for purpose.
In-line with HSE guidance, hot water is distributed throughout the hospital at 60°C. SECURITHERM thermostatic point-of-use mixers are installed on the Cardiology Ward where patients are the primary user and the risk of scalding is higher (the elderly, infirm and people with reduced mobility). The mechanism adjusts to temperature variations at the hot and cold inlets to ensure a safe, constant mixed water temperature, and a maximum temperature limiter plus cool-touch body mitigate that risk. The mixer shuts off completely if the hot or cold water supply fails, removing the risk of scalding. Moreover, the mixing chamber is at the point-of-use so there are no systemic dead legs where bacteria can develop.
The Intensive Care Unit has a lower level of risk since the patients are too poorly to use the sinks. Clinical staff are familiar with the facilities and signage clearly states the scalding risk. Here SECURITHERM EP mixers with pressure-balancing are installed. The mechanism responds to pressure variations and adjusts the hot or cold inlet accordingly delivering a constant water temperature. If the cold supply fails, the hot water is reduced to a trickle. The SECURITHERM EP also features a maximum temperature limiter and cool-touch body.
In the new Delivery Suite, Phil has proposed a Securitouch mixer with a ceramic cartridge. Here the risk of infection is far more significant than the risk of scalding. The mixer has a maximum temperature limiter and thermal insulation to prevent burns and scalds, but the priority is reducing the spread of germs. The water volume in the mixer is significantly reduced, minimising standing water where bacteria develop. The mixer has a smooth interior with fewer niches for waterborne bacteria to adhere, and the spout can be removed entirely for disinfection.
Easy to install and maintain
The appeal of DELABIE’s mixers for Phil Mitchell is the ease with which they are installed and maintained. DELABIE’s SECURITHERM, SECURITHERM EP and Securitouch mixers have standard 150mm centres and connect in front of the IPS panel. Stopcocks in the connectors mean that the water supply can be shut-off in front of the panel for de-scaling or maintenance. Since the connectors are standardised, Phil keeps a stock of the different wall-mounted mixers which can then be installed easily at any point-of-use, especially if wards are re-purposed and the scalding risk changes.
To comply with D08 requirements, thermostatic mixing valves must be regularly serviced and the anti-scalding failsafe checked. Servicing the DELABIE thermostatic mixers is less onerous since the mechanism is easily accessed in front of the IPS panel. The cartridge is integrated in the mixer body and is accessed by removing the control lever using an Allen key. The hot water failsafe can also easily be checked via the wall connectors.
Deck-mounted versions of the SECURITHERM mixers have been installed in the patient toilet facilities at the hospital. The mixer is mounted on a solid brass base. Using a standard Allen key, the mixer can be removed entirely from its base for cleaning and disinfection and if more in-depth maintenance is required, an alternative body can be installed to ensure continuity of use.
No compromise solutions
The John Radcliffe hospital has become an example of best practice for NHS Trust teams. Through the application of a risk-based analysis, and installing mixers that are appropriate to the use, Phil Mitchell and the estates team have simplified their maintenance routine and ensured continuity of delivery even when wash stations and toilet facilities are re-purposed. At no point has patient/user safety been compromised and the risk of infection has been minimised.
Written by Carole Armstrong, Marketing & Communications Manager
To find out more, please watch the video or get in touch: Delabie UK Ltd, Henderson House, Hithercroft Road, Wallingford, OX10 9DG