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 & Safety Executive ban on the use of elemental copper as a biocide, particularly for legionella control.

“HSE's 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. In addition, HSE intends to pursue an 'essential use derogation' for use of copper in legionella control systems in the Uk,” said HSE.

“We encourage users of these water treatment systems to contact the manufacturer to discuss a way forward.”

Bob Wilson, principal of Meadowhead Consultancy, an independent expert on the efficacy of anti-legionella treatments, has been looking at the options available and said building and facilities managers should take action immediately.

Wilson explained that L8, the legislation and Approved Code of Practice for the control of Legionella, mentions two possibilities for continuous dosing of building water systems. These are firstly, chlorine dioxide and secondly, copper/silver ionization.

“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,” said Wilson.

“As silver may be added to the water, the best treatment is probably one that combines hydrogen peroxide and activated silver,” he added. “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.”

Companies that have any further concerns about the biocidal use of elemental copper should email the biocides helpdesk.