Frequently Asked Questions
What is Legionella?
Legionella bacteria is commonly found in water. The bacteria multiply where temperatures are between 20-45°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C. Legionnaires’ disease is a potentially fatal type of pneumonia, contracted by inhaling airborne water droplets containing viable Legionella bacteria. Such droplets can be created, for example, by: hot and cold water outlets; atomisers; wet air conditioning plant; and whirlpool or hydrotherapy baths.
What is Legionnaires Disease?
Legionnaires disease is a kind of pneumonia which affects the lungs. People can catch legionnaires disease from inhaling droplets or aerosol from water systems contaminated with legionella bacteria. Every body is susceptible to legionnaires disease, however some people will be more susceptible. Legionnaires disease is not contagious, however a contaminated water system has the potential to spread to many users.
Do I Need a Legionella Risk Assessment?
If you own, manage or are responsible for the property, it is your responsibility to carry out a legionella risk assessment and act on any findings to ensure persons using the facilities are safe from exposure.
‘Duties under the Health and Safety at Work etc Act 1974 (HSWA) extend to risks from legionella bacteria, which may arise from work activities. The Management of Health and Safety at Work Regulations (MHSWR) provide a broad framework for controlling health and safety at work. More specifically, the Control of Substances Hazardous to Health Regulations 2002 (COSHH) provide a framework of actions designed to assess, prevent or control the risk from bacteria like Legionella and take suitable precautions.
As an employer, or a person in control of the premises, you are responsible for health and safety and need to take the right precautions to reduce the risks of exposure to legionella. You must understand how to:
- identify and assess sources of risk
- manage any risks
- prevent or control any risks
- keep and maintain the correct records
- carry out any other duties you may have
Identify and assess sources of risk
Carrying out a risk assessment is your responsibility. You may be competent to carry out the assessment yourself but, if not, you should call on help and advice from either within your own organisation or from outside sources, eg consultancies.
You or the person responsible for managing risks, need to understand your water systems, the equipment associated with the system such as pumps, heat exchangers, showers etc, and its constituent parts. Identify whether they are likely to create a risk from exposure to legionella, and whether:
- the water temperature in all or some parts of the system is between 20–45 °C
- water is stored or re-circulated as part of your system
- there are sources of nutrients such as rust, sludge, scale, organic matter and biofilms
- the conditions are likely to encourage bacteria to multiply
- it is possible for water droplets to be produced and, if so, whether they can be dispersed over a wide area, eg showers and aerosols from cooling towers
- it is likely that any of your employees, residents, visitors etc are more susceptible to infection due to age, illness, a weakened immune system etc and whether they could be exposed to any contaminated water droplets’
above taken from HSE -Legionnaires' disease - What you must do
How can I arrange for a legionella risk assessment to be carried out?
If you have the knowledge and competence, you are able to complete a legionella risk assessment yourself, however it is probably best to arrange for an independent risk assessment from a specialist. Please contact us for more information and a survey.