Legionnaires' disease is a type of pneumonia, caused by the bacteria Legionella Pneumophillia. People catch legionnaires' disease by inhaling small droplets of water suspended in the air (aerosol), which contain the bacteria.

Approved Code of Practice

This is aimed at dutyholders, including employers, those in control of premises and those with health and safety responsibilities for others, to help them comply with their legal duties in relation to legionella. These include identifying and assessing sources of risk, preparing a scheme to prevent or control risk, implementing, managing and monitoring precautions, keeping records of precautions and appointing a manager to be responsible for others.

This fourth edition of the ACOP and guidance on regulations contains revisions to simplify and clarify the text. The main changes are removing Part 2, the technical guidance, which is published separately in HSG274, and giving the following issues ACOP status:

  • risk assessment
  • the specific role of an appointed competent person, known as the ‘responsible person’
  • the control scheme
  • review of control measures
  • duties and responsibilities of those involved in the supply of water systems

Guidance note

The maintenance of a water system in a clean state is an important part of managing the risk from legionella. The removal of pack from a cooling tower for assessment of cleanliness as part of a cleaning regime is an issue which causes confusion and conflict for cooling tower users, water treatment companies, other service providers and inspectors of health and safety.

The "Removal of Pack from Cooling Towers" HSE guidance note aims to clarify the guidance given in L8 and promote a consistency of approach to the need for removal of pack by providing advice on the factors which may inform decisions on pack removal for cleaning and inspection.


Key legislation

Please note that this link is to the original legislation. Visitors should verify for themselves whether legislation is in force or whether it has been amended or repealed by subsequent legislation.