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Legionnaires' disease

Legionnaires’ disease is a type of pneumonia caused by Legionella bacteria.


Legionnaires’ disease takes between two to ten days for symptoms to appear. Symptoms include malaise, headache, chills, rapid onset of high fever, cough, and other influenza-like symptoms. Legionnaires’ disease can be life threatening. Risk of infection is a combination of two factors – the amount of Legionella bacteria to which the body is exposed and the resistance of the individual to the bacteria. Consequently it is only possible to make general statements about risk however risk is increased for those whose immune system is already under stress for any reason, including illness or medical treatment, such as radiation therapy. Diabetics, those suffering chronic lung, heart or kidney disease, aged persons, smokers and heavy drinkers also have some increased risk.


The key to reducing the risk of contracting Legionnaires’ disease is to minimise the risk of exposure to Legionella bacteria. This is achieved by effective management of air conditioning cooling towers, warm water systems and other such plant that afford optimum conditions for Legionella growth in addition to providing a means of dispersal.

Employers generally contract out cooling tower maintenance functions or, where the employer is a lessee, such services may generally be undertaken by building owners/managers. In these cases, the following steps will assist employers to meet their work health and safety (WHS) obligations under the Work Health and Safety Act 2011:

  • Ensure there is a formal, enforceable agreement with building management/contractors (e.g. lease, service contract) clearly setting out maintenance and testing procedures and ensuring compliance with measures outlined in AS/NZS 3666.
  • Ensure the above mentioned agreement includes timing, content and format of maintenance reports, consistent with that contained in Section 10 of AS/NZS 3896.
  • Implement in full, all requirements as detailed in the Code of Practice on Managing the Work Environment and Facilities


Information sourceContents
Code of Practice - How to Manage Work Health and Safety RisksThis code provides practical guidance for persons who have duties under the WHS Act and Regulations to manage risks to health and safety.
Safe Work Australia - Code of Practice for Managing the Work Environment and FacilitiesRisk management framework for managing the work environment and facilities within it. Please note this is guidance only and not a legislative instrument.
UK Health & Safety Executive (HSE) - Legionella and Legionnaires' diseaseGeneral information regarding Legionnaires’ disease from the United Kingdoms Health and Safety Executive.
UK Health & Safety Executive (HSE) - Legionnaires' disease FAQ 
  • AS/NZS 3666 parts 1-3, Air-handling and water systems of buildings – Microbial Control
  • AS/NZS 3896 Waters – Examination for legionellae including Legionella pneumophila
  • AS 1668 part 2, The use of mechanical ventilation and air-conditioning in buildings
  • SAA/SNZ HB32 Control of microbial growth in air-handling and water systems of buildings.


Information sourceWhat it contains
Incident notification - Part 3, Section 35 to 37 of the Work, Health and Safety Act 2011The legislative requirements for incident notification to Comcare.
Comcare - Guide to incident notificationHelps you decide whether you need to notify Comcare of an injury, illness or dangerous incident under the WHS Act.
Page last updated: 10 May 2019