Legionella - Risk Assessments

The control of Legionella bacteria in water systems.
The Approved Code of Practice.

• Control of substances Hazardous to Health Regulations 1999, Regulation 6
• Management of Health and Safety at Work Regulations 1999, Regulation 3
• Health and safety at Work etc Act 1974, Sections 2,3 and 4

Paragraphs 23 - 31
23 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 assessment is carried out by or on behalf of:

• the employer, where the risk from their undertaking is to their employees or to others; or
• a self employed person, where there is a risk from their undertaking to themselves or to others; or
• the person who is in control of the premises or systems in connection with work where the risk is present from the systems in the building (eg where the building is let to tenants but the landlord retains responsibility for its maintenance)

24 In conducting the assessment, the person on whom the statutory duty falls is required to have access to competent help to assess the risks of exposure to Legionella bacteria in the water systems present in the premises and the necessary control measures.

25 The assessment should include identification and evaluation of potential sources of risk and:

• the particular means by which exposure to Legionella bacteria is to be prevented; or
• if prevention is not reasonably practicable, the particular means by which the risk from exposure to Legionella bacteria is to be controlled.

26 Where the assessment demonstrates that there is no reasonably foreseeable risk or that risks are insignificant and unlikely to increase, no further assessment or measures are necessary. However, should the situation change, the assessment needs to be reviewed and any necessary changes implemented.

27 The assessment needs to be reviewed regularly and, in any case, whenever there is reason to believe that the original assessment may no longer be valid.

28 Before any formal health and safety management system for water systems can be implemented, a risk assessment has to be carried out to decide the possible risks. The purpose of the assessment is to enable a decision to decide

• the risk to health, ie whether the potential for harm to health from exposure is reasonably foreseeable unless adequate precautionary measures are taken;
• the necessary measures to prevent, or adequately control, the risk from exposure to Legionella bacteria.

29 The risk assessment also enables the person on whom the statutory duty falls to show that all pertinent factors, and the steps needed to prevent or control the risk, have been considered.

30 In conducting the assessment, the person on whom the statutory duty falls need to have access to competent help and advice. This source of advice may not necessarily be within the person's organisation but may be from a consultancy, water treatment company or a person experienced in carrying out risk assessments. Employers are required to consult employees or their representatives about the arrangements for getting competent help and advice.

31 It is the duty of the responsible person to make all reasonable enquiries to ensure that organisations such as water treatment companies or consultants, together with personnel from the occupier's organisation, are competent and suitably trained and have the necessary equipment to carry out their duties within the written scheme in a safe and adequate manner.