The COSHH Regulations cover hazards from micro-organisms and up to 200 cases of Legionella are reported in England and Wales each year.

Occupiers of non-domestic properties must inform local authorities in writing if a 'notifiable device' exists on the premises. A notifiable device is a cooling tower or evaporative condenser. If in doubt consult the Notification of Cooling Towers and Evaporative Condensers Regulations 1992.

Employers and occupiers must risk assess for Legionella (and keep records) in the following circumstances;

The building contains water cooling towers or evaporative condensers. There are hot water services with volumes exceeding 300 litres. There are hot or cold water services which are particularly susceptible e.g. in hospitals or nursing homes. Humidifiers or air washers are used which create water droplets and where the water temperature is 20 degrees C or more. Baths/pools or spas where warm water is recirculated.

A professional survey of the equipment/system will usually be required.

It is worth noting that prosecutions have been successful even where no one has actually contracted legionellosis. It is merely sufficient to have Legionella present to be at fault.

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