The approved code of practice Scope and application
Acop
This Approved Code Of Practice applies to the control of legionella bacteria in any undertaking involving a work activity and to premises controlled in connection with a trade, business or other undertaking where water is used or stored and where there is a means of creating and transmitting water droplets which may be inhaled, thereby causing a reasonably foreseeable risk of exposure to legionella bacteria.
A reasonably foreseeable risk of exposure to legionella bacteria exists in:
water systems incorporating a cooling tower; water systems incorporating an evaporative condenser; hot and cold water system; and other plant and systems containing water which is likely to exceed 20C and which may release a spray or aerosol (i.e. a cloud of droplets and/or droplet nuclei) during operation or when being maintained.

Guidance
Experience has shown that cooling towers, evaporative condensers and hot and cold water systems in a wide variety of workplaces present a risk of exposure to legionella bacteria. Not all of systems will require elaborate assessment and control measures. A simple risk assessment may show that the risks are low and, in such case, no further action will be necessary. Examples include small, domestic-type water systems where temperatures and turnover are high, or where instantaneous water heaters are used.
A water system includes all plant/equipment and components associated with that system, e.g. all associated pipe-work, pumps, feed tanks, valves, showers, heat exchangers, quench tanks, chillers etc. It is important that the system is considered as a whole and not, for example, the cooling tower in isolation. Deadlegs and parts of the system used intermittently, e.g. test loops in engineering factories and injection moulding machines, also need to be included as part of the system since they can create particular problems with microbial growth going unnoticed. Once brought back on-line, they can cause heavy contamination which could disrupt the efficiency of the water treatment regime.
For other systems, such as humidifiers and air washers, spa baths and pools, car/bus washes, wet scrubbers, indoor fountains and water features, advice on control measures is given in other text.

< Back - Next >