As a Legionella outbreak grips Edinburgh, anti-scald tap, valve and shower manufacturer Inta reminds engineers and installers how to safeguard against the bacteria without running the risk of bathroom scalding.

Stuart Gizzi, director at Inta, explains: “The outbreak of Legionella in Scotland, which to date has claimed the lives of two and infected over 80 more, is a worrying state of affairs.

“Although in this instance the outbreak is thought to originate from cooling towers which have a whole different maintenance regime to bathrooms, it has proven to be a painful reminder of how necessary it is to take precautions against the infection, whether it be in the home or in a care or commercial setting.

“We have been promoting anti-scald education for many years and both our publications and online resources include information about reducing the risk of Legionella and quite simply correct specification and installation, followed by scheduled maintenance checks is the key.

“Legionella is a bacterium that thrives in tepid and warm water, at temperatures of around 20 - 45 degrees and can occur when taps and showers have been left unused for a considerable period of time. Large buildings such as hotels, hospitals, schools and office blocks can be more susceptible to contamination, as they have larger complex water supply systems where bacteria can easily thrive.

“The obvious solution is to heat water to very high temperatures in order to destroy the bacteria, but a concerning number of bathrooms and washrooms are not fitted with the sort of technology that can bring the water back down to safe temperatures for the user. This is a dangerous trade-off, as even moderately hot water can cause as much, if not more, physical harm as the risk of Legionnaires disease. Nursing and residential care homes tend to heat water to incredibly high temperatures for effective kitchen and laundry use. In these cases, the fitting of TMV3 thermostatic mixing valve close to the outlet is mandatory and is the only way to safeguard against both scalding and Legionella.

“Under health and safety law, all companies, establishments and services “have to consider the risks from Legionella that may affect your staff or members of the public and take suitable precautions.” Employers or persons in control of premises must identify and assess sources of risk, prepare a course of action for preventing or controlling the risk, keep records of checks and changes and nominate a specific person to carry out the above responsibilities.

“A duty also lies with any persons involved in the supply of water systems and their components to inform the appointed person of the risks that may be present and ensure that equipment is designed and made in such a way that it is safe to use at work and easy to clean and maintain.

“Preventing Legionella and scalding can be easy with products that do it for you, but there are still millions of bath and washrooms in the UK without any form of precautionary technology. We would always advise that washrooms are maintained and routinely checked. Part of this upkeep should include flushing taps with hot water regularly, but only when they are isolated from use, in addition to using appropriate water treatments, cleaning products and disinfectants.

“A risk assessment should be carried out every two years and more frequently if there have been changes to the water systems or the building use. It is vital that checks are carried out, as Legionella can thrive in domestic buildings water systems where there is a build-up of sediment - something that both hot water and chemical treatments cannot prevent. While it may seem tedious, these simple steps ensure safety is always high on the agenda - with absolutely no compromise.

“It is a fair assumption that products have been correctly specified and fitted. The most important thing is to remember to carry out the scheduled maintenance - something installers should be mindful to communicate to customers who, without the levels of plumbing expertise, need guidance and education to make bathrooms safe.”

For more information please visit or call 01889 272 180. For further advice from the Health and Safety Executive visit