Copper banned for legionella control
Following a ban on the marketing and use of elemental copper to add copper ions to water as a biocide for water treatment, the Health & Safety Executive has applied to the European Commission for an ‘essential use derogation’ to allow for the continued use of copper in legionella control systems in the UK. The ban came into effect on 1 February under the ‘Biocidal Products Directive’ and the national ‘Biocidal Products Regulations 2001’, which implement the directive in Great Britain. This action has been taken at EU level because no manufacturer supported the biocidal use of elemental copper during a review period that ended in September 2011.
Until the outcome of the application is known, HSE’s primary concern is that legionella control is not compromised. A statement from HSE says, ‘HSE inspectors will take a sensible and proportionate approach to enforcement if we come across any of these systems after 1 February. The focus of any enforcement activity will be on the failure to control the risk of exposure to legionella bacteria and the likelihood of Legionnaires’ Disease developing in a given situation.’
Systems that only add silver ions to the water are not affected.
Options appear to be limited. According to Bob Wilson, principal of Meadowhead Consultancy, ‘L8, the legislation and Approved Code of Practice for the control of legionella mentions only two possibilities for the continuous dosing of building water systems. They are chlorine dioxide and copper/silver ionisation.’
Since silver may be added to the water, he suggests that ‘the best treatment is probably one that combines hydrogen peroxide and activated silver’. That treatment was used at the London 2012 Olympics instead of chlorine to disinfect athletes’ ice baths, therapy, treatment and training pools. Mr Wilson also says that it is widely used for one-off disinfections and, increasingly, as a continuous-dose chemical.
