Legionellosis Prevention

Legionellosis is a collective term for diseases caused by legionella bacteria. The most serious of these diseases is Legionnaire’s disease, a potentially fatal form of pneumonia. Legionnaire’s disease is contracted by inhaling small droplets of water (aerosols) suspended in the air which contain the bacteria. 

The risk of contracting Legionnaire’s disease increases with age, amongst smokers, anyone suffering from chronic respiratory or kidney disease or with an impaired immune system. Risks can also increase in buildings using air conditioners or humidifiers, buildings with dead end pipes, long runs of pipework containing warm water, or indoor ornamental fountains and showers.

• Complete, record and revise risk assessments to identify where precautions are required
• Eliminate any hazardous substances that are present if possible
• Implement suitable precautions to be taken where hazardous substances are present
• Ensure precautions are taken and properly maintained
• Provide information and training to employees, volunteers, and contractors

• Water stored or re-circulated as part of the water system
• Water temperatures between 20-45ºC
• Sources of nutrients such as rust, sludge, scale, and organic matter that encourage bacterial growth
• Water droplets being produced and dispersed over a wide area
• Employees, volunteers, and visitors who are more susceptible to infection
• The use of humidifiers and air-conditioners

• Avoid water temperatures and conditions that flavour the growth of legionella
• Ensure that the release of water spray is properly controlled
• Make sure water cannot stagnate anywhere in the system
• Keep the water and water system clean
• Treat water to control the growth of legionella
• Arrange for air-conditioners and humidifiers to be cleaned and serviced regularly
• De-scale shower heads and running showers periodically