Legionella Risk Assessment- Information Sheet
Background
Legionella bacteria are ubiquitous in nature and commonly colonise air conditioning plant, water storage tanks, hot and cold water distribution systems and spa baths. Where conditions are right the bacteria can multiply to significant numbers and present a risk. Infection is caused by the inhalation of Legionella bacteria in the form of an aerosol. To cause infection the bacteria therefore needs to become airborne for example from a shower, spray tap or cooling tower.
Legionellosis is a generic term given to respiratory infections, such as Legionnaire’s disease, caused by Legionella bacteria. Over thirty nine different species of Legionella have been identified. Only a few species have been directly associated with outbreaks of infection. Legionella pneumophila Serogroup 1 is the most commonly identified form of the bacteria and is responsible for over 80% of the fatalities arising from Legionnaire’s disease. On average there are around 200 – 250 reported cases of Legionnaires’ disease in the United Kingdom per annum.
Guidance and Legislation
The requirement to consider, prevent and control the risk from Legionella bacteria which may arise from work activities is covered as part of the duties under the Health and Safety at Work Act 1974. Within the framework of health and safety legislation other regulations are relevant, particularly the Control of Substances Hazardous to Health Regulations and the Management of Health and Safety at Work Regulations.
In support of the legislative documents the Health and Safety Commission in the UK has published an Approved Code of Practice, L8, ‘The Control of Legionella Bacteria in Water Systems’ (ACoP, L8) setting out requirements and guidance on the measures to be taken to prevent or control the risk from Legionella bacteria. The ACoP, L8, Paragraph 4 states:
To comply with their legal duties, employers and those with responsibilities for the control of premises should:
- identify and assess sources of risk;
- prepare a scheme for preventing or controlling the risk;
- implement, manage and monitor precautions;
- keep records of the precautions; and
- appoint a person to be managerially responsible
Risk Assessment
The ACoP, L8, sets out that:
‘a suitable and sufficient assessment is required to identify and assess the risk of exposure to Legionella bacteria from work activities and water systems on the premises and any necessary precautionary measures’.
The purpose of the assessment is to enable valid decisions to be made about the level of risk to health and measures for prevention or control. The risk assessment is carried out by or on behalf of the Duty Holder. The Duty Holder is identified as the employer; or a self-employed person; or the person who is control of premises or systems where others may be affected, such as in landlord/tenant situations or public premises.
The Duty Holder must appoint a person to be responsible for identifying, controlling and managing the risk from Legionella. This person is termed the Responsible Person and is responsible for ensuring that risk assessment is undertaken, recorded and maintained up to date. The risk assessment should identify and evaluate potential sources of risk and in particular:
- the means by which exposure to legionella bacteria is to be prevented; or
- if prevention is not reasonably practicable, the means by which the risk from exposure to legionella bacteria is to be controlled.
The assessment of risk should take into account aerosol formation and dissemination; Legionella contamination and proliferation; potential exposure of persons and their susceptibility; adequacy of control measures and management control procedures
Risk Assessment Status and Review
The ACoP, L8, requires that the risk assessment be reviewed every two years and will require additional review in the interim where changes occur. The requirement to review the risk assessment may result when;
- changes are made to the water systems;
- changes are made to the management and control systems;
- further information is provided on the systems or control measures;
- results show the risk control programme is not working effectively;
- following reported or suspected cases of Legionnaires disease associated with the system.
Legionella Control Association
The Legionella Control Association is an organisation formed jointly by the Water Management Society and British Association for Chemical Specialities. The association operates to set out auditable requirements in the form of a code of conduct for service providers involved with the control of Legionella. The aim is to provide assurance to end users that the advice and services provided by companies are technically sound; identify lines of communication and responsibilities; and that staff employed to perform the actions are suitably trained. Legionella Control Association registered companies should be employed where possible when water management services are required.
First Environment Limited is an independent specialist consultancy providing support on safety, health and environmental issues. First Environment is a registered company with the Legionella Control Association and holding Tier 1 status. In compliance with our service provider commitments a copy of our registration certificate can be accessed here.
Further Advice
The Health and Safety Executive has published a leaflet, Legionnaire’s disease: A guide for employers, IAC27. This can be obtained free of charge from the Health and Safety Executive web site www.hse.gov.uk/pubns/iacl27.pdf and this site also provides access to further articles and information.