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Urgent review of anti-legionella water treatment essential

Published 22nd February, 2013 by Neil Nixon

Urgent review of anti-legionella water treatment essential

Thousands of property managers responsible for public buildings are being forced to carry out urgent reviews and source alternative water treatments following the recent Health and Safety Executive (HSE) ban on the use of elemental copper as a biocide, particularly for legionella control.

The HSE says it 'will be illegal to sell or use water treatment systems that use elemental copper in order to add copper ions to water as a biocide. It will also be illegal to supply the copper needed for their use.' The decision has been taken following a review by the EU under the Biocidal Products Directive.

Bob Wilson, principal of Meadowhead Consultancy Ltd, an independent expert on the efficacy of anti-legionella treatments, has been looking at the options available and how building managers should review them: “From owners of apartments, office blocks, shopping centres to hospitals, hotels, schools, factories and sports arenas, facilities managers of these premises must take action immediately. The deadline is looming and the HSE says its 'primary concern is that legionella control is not compromised. Businesses and organisations have a responsibility to manage the risks from legionella and it is essential that these duties continue to be met.' L8, the legislation and approved code of practice for the control of Legionella, only mentions two possibilities for continuous dosing of building water systems. These are, firstly, chlorine dioxide and secondly, copper/silver ionisation. The demise of copper/silver ionisation suggests that chlorine dioxide is the only viable alternative. Chlorine dioxide is a toxic gas which must be produced by mixing two chemicals. The gas is then introduced into the water system. This requires expensive dosing equipment to ensure this is done safely. Chlorine dioxide is known to be corrosive, and long term dosing will result in an increased maintenance spend. The product gases off in calorifiers, resulting in inadequate treatment and possible legionella proliferation.”

Bob Wilson continued: “As silver may be added to the water, the best treatment is probably one that combines Hydrogen Peroxide and Activated Silver such as EndoSan. This was used at the London 2012 Olympics, instead of chlorine, to disinfect athletes' ice baths, therapy, treatment and training pools. It is also widely used for one-off disinfections and increasingly, as a continuous dose chemical.”

Phil Buchanan, managing director of Endo Enterprises, a disinfection and infection control company based in Salford Quays in Manchester, said: “Independent analysis has shown that EndoSan offers many advantages over chlorine dioxide and overall is probably the most highly cost-effective option to replace copper ionisation treatments. EndoSan is more effective than chlorine dioxide for removing biofilm, it is much less corrosive and far more stable. EndoSan is equally effective at high and low temperatures and is independent of pH. EndoSan is easy to dose using inexpensive dosing systems which means that domestic hot water temperatures can be reduced and energy saved. Following risk assessment in compliance with L8, many water treatment facilities, estates management groups, and health care operators, utilise EndoSan and our constant dosing system as the preferred method of Legionella control, throughout the UK.”

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