Legionnaires' disease. The control of legionella bacteria in water systems

Health and Safety

Legionnaires’ disease The control of legionella bacteria in water systems

Approved Code of Practice and guidance on regulations This book is aimed at dutyholders, including employers, those in control of premises and those with health and safety responsibilities for others, to help them comply with their legal duties in relation to legionella. These include identifying and assessing sources of risk, preparing a scheme to prevent or control risk, implementing, managing and monitoring precautions, keeping records of precautions and appointing a manager to be responsible for others.

This fourth edition of the ACOP and guidance on regulations contains revisions to simplify and clarify the text. The main changes are removing Part 2, the technical guidance, which is published separately as HSG274 at www.hse.gov.uk/pubns/books/hsg274.htm, and giving the following issues ACOP status:

■■ risk assessment; L8 (Fourth edition) ■■ the specific role of an appointed competent person, known as the Published 2013 ‘responsible person’; ■■ the control scheme; ■■ review of control measures; ■■ duties and responsibilities of those involved in the supply of water systems.

HSE Books

© Crown copyright 2013

First published 1991 Second edition 1995 Third edition 2000 Fourth edition 2013

ISBN 978 0 7176 6615 7

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Approved Code of Practice

This Code has been approved by the Health and Safety Executive, with the consent of the Secretary of State. It gives practical advice on how to comply with the law. If you follow the advice you will be doing enough to comply with the law in respect of those specific matters on which the Code gives advice. You may use alternative methods to those set out in the Code in order to comply with the law.

However, the Code has a special legal status. If you are prosecuted for breach of health and safety law, and it is proved that you did not follow the relevant provisions of the Code, you will need to show that you have complied with the law in some other way or a Court will find you at fault.

Guidance

This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory, unless specifically stated, and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance.

Cover photograph by kind permission of Public Health England.

Contents

Introduction 5 About this book 5 About ACOPs 6 Presentation 6 Legionnaires’ disease 6 Health and safety law 7 Scope and application 10 Identification and assessment of the risk 11 Carrying out a risk assessment 12 Managing the risk: Management responsibilities, training and competence 14 Competence 15 Implementation of the control scheme 15 Preventing or controlling the risk from exposure to legionella bacteria 16 Review of control measures: Monitoring and routine inspection 18 Record keeping 19 Responsibilities of designers, manufacturers, importers, suppliers and installers 20 Appendix 1 Notice of Approval 23 Glossary 24 References and further reading 26 Further information 28

Introduction

About this book

1 This Approved Code of Practice (ACOP) gives advice on the requirements of the Health and Safety at Work etc Act 1974 (the HSW Act)1 and the Control of Substances Hazardous to Health Regulations 2002 (COSHH)2 and applies to the risk from exposure to legionella bacteria (the causative agent of legionellosis, including Legionnaires’ disease). In particular it gives guidance on sections 2, 3, 4 and 6 of the HSW Act and regulations 6, 7, 8, 9 and 12 of COSHH. The Code also gives guidance on compliance with the relevant parts of the Management of Health and Safety at Work Regulations 1999 (the Management Regulations).3

2 This book is for dutyholders, which includes employers and those with responsibilities for the control of premises, eg landlords. To comply with their legal duties, dutyholders should:

(a) identify and assess sources of risk. This includes checking whether conditions will encourage bacteria to multiply. For example, if the water temperature is between 20–45 °C, if there is a means of creating and disseminating breathable droplets, such as the aerosol created, eg by cooling towers, showers and spa pools; and if there are ‘at risk’ susceptible people who may be exposed to the contaminated aerosols (see paragraphs 28–47); (b) if appropriate, prepare a written scheme for preventing or controlling the risk (see paragraphs 58–64); (c) implement, manage and monitor precautions – if control measures are to remain effective, regular monitoring of the systems and control measures is essential (see paragraphs 65–69). Monitoring general bacterial numbers can indicate whether you are achieving microbiological control and sampling for legionella is another means of checking that a system is under control (see paragraph 68); (d) keep records of the precautions (see paragraphs 70–74); (e) appoint a competent person with sufficient authority and knowledge of the installation to help take the measures needed to comply with the law (see paragraphs 48–51).

3 The Code and guidance also set out the responsibilities of suppliers of services such as water treatment and maintenance; and designers, manufacturers, importers, suppliers and installers of systems (see paragraphs 75–85).

4 This fourth edition of the ACOP and guidance on regulations contains revisions to simplify and clarify the text. The main changes are:

(a) removing Part 2, the technical guidance, which is now published separately at www.hse.gov.uk/pubns/books/hsg274.htm and has three parts: Part 1: Evaporative cooling systems; Part 2: Hot and cold water systems and Part 3: Other risk systems; (b) guidance on the following issues now has ACOP status:

(i) risk assessment; (ii) the specific role of the appointed competent person, known as the ‘responsible person’; (iii) the control scheme and what it should include; (iv) review of control measures; (v) duties and responsibilities of those involved in the supply of water systems including suppliers of services, designers, manufacturers, importers, suppliers and installers of water systems.

About ACOPs

5 ACOPs are approved by the HSE Board with the consent of the Secretary of State (see ‘Appendix 1: Notice of Approval’ for details).

6 The ACOP describes preferred or recommended methods that can be used (or standards to be met) to comply with the Regulations and the duties imposed by the Health and Safety at Work etc Act 1974. The guidance also provides advice on achieving compliance, or it may give general information, including explaining the requirements of the law, more specific technical information or references to further sources of information.

7 The legal status of the ACOP and guidance text is clearly outlined on page 2.

Presentation

8 The ACOP text is set out in bold, and guidance is in normal type and the reference to the regulation(s) is in italics. Coloured borders indicate each section clearly.

9 Each regulation reference is followed by a short summary of the main duties imposed by that regulation and aims to help the reader navigate the document. This text is for information and does not have ACOP or guidance status.

Legionnaires’ disease

10 Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. The risk increases with age, but some people are at higher risk, eg people over 45, smokers and heavy drinkers, people suffering from chronic respiratory or kidney disease, diabetes, lung and heart disease or anyone with an impaired immune system.

11 The bacterium Legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems, such as cooling towers, evaporative condensers, hot and cold water systems and spa pools. If conditions are favourable, the bacteria may multiply, increasing the risks of legionnaires’ disease, and it is therefore important to control the risks by introducing appropriate measures.

12 Legionella bacteria are widespread in natural water systems, eg rivers and ponds. However, the conditions are rarely conducive for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth, eg cooling towers, evaporative

condensers, hot and cold water systems and spa pools used in all sorts of premises (work and domestic).

13 Legionnaires’ disease is normally contracted by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria. Certain conditions increase the risk from legionella if:

(a) the water temperature in all or some parts of the system may be between 20–45 °C, which is suitable for growth; (b) it is possible for water droplets to be produced and if so, they can be dispersed; (c) water is stored and/or re-circulated; (d) there are deposits that can support bacterial growth, such as rust, sludge, scale, organic matter and biofilms.

14 It is important to control the risks by introducing measures which do not allow proliferation of the organisms in the water systems and reduce, so far as is reasonably practicable, exposure to water droplets and aerosol. This will reduce the possibility of creating conditions in which the risk from exposure to legionella bacteria is increased.

Health and safety law

15 Duties under the HSW Act apply to the risks from exposure to legionella bacteria that may arise from work activities. The Management Regulations provide a broad framework for controlling health and safety at work. As well as requiring risk assessments, they also require employers to have access to competent help in applying the provisions of health and safety law; to establish procedures for workers if there are situations presenting serious, imminent danger; and for co-operation and co-ordination where two or more employers or self-employed people share a workplace. More specifically, COSHH provides a framework of actions designed to control the risk from a range of hazardous substances, including biological agents.

Information box: Summary of the HSW Act, sections 2, 3 and 4

Section 2 places a duty on employers to ensure the health, safety and welfare of employees so far as reasonably practicable (SFARP). More guidance on the principles of SFARP may be found on the HSE website (www.hse.gov.uk/risk/ theory/alarp1.htm). Section 2 also requires employers to consult with trade union safety representatives on matters affecting health and safety in the workplace. Employers of more than five people must also prepare a written health and safety policy and bring it to the attention of employees.

Section 3 requires employers to ensure that non-employees who may be affected by work activities are not exposed to risks to their health and safety.

Section 4 places a duty on anyone responsible for the workplace to ensure that the premises, plant and machinery do not endanger the people using them.

16 Only the courts can give an authoritative interpretation of law on the application of these Regulations and guidance to people working under another’s direction. If people working under the control and direction of others are treated as self-employed for tax and national insurance purposes, they may nevertheless be treated as employees for health and safety purposes. So, it may be necessary to take appropriate action to protect them. If there is any doubt about who is

responsible for the health and safety of a worker, clarify this and include it in the terms of a contract. However, a legal duty under section 3 of the HSW Act cannot be passed on by means of a contract. You will still have duties towards others under section 3 of the HSW Act. If you employ workers on the understanding that they are responsible for their own health and safety, seek legal advice before doing so. For section 3 to apply:

(a) there must be a dutyholder – either an employer or a self-employed person; and (b) there must be a risk to the health or safety of a person who is not an employee of the dutyholder or the self-employed dutyholder themselves; and (c) that risk must arise from the conduct of the dutyholder’s undertaking. ‘Undertaking’ means ‘enterprise’ or ‘business’.

Section 3 does not apply to:

(d) welfare issues (such as the provision of toilets or washing facilities); (e) nuisance or amenity issues that have no health or safety implications (such as unpleasant smells arising from work activities); (f) poor workmanship, where trading standards or contractual remedies may exist, unless they have demonstrably compromised health and safety.

17 COSHH provides a framework of actions designed to control the risk from a range of hazardous substances, including biological agents. The essential elements of COSHH are:

(a) risk assessment; (b) where reasonably practicable, prevention of exposure or substitution with a less hazardous substance, or substitution of a process or method with a less hazardous one; (c) control of exposure, where prevention or substitution is not reasonably practicable; (d) maintenance, examination and testing of control measures; (e) provision of information, instruction and training for employees; (f) health surveillance of employees (where appropriate, and if there are valid techniques for detecting indications of disease) where exposure may result in an identifiable disease or adverse health effect.

18 The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR)4 require employers and others, eg someone who has control of work premises, to report to HSE, accidents and some diseases that arise out of or in connection with work. Cases of legionellosis are reportable under RIDDOR if:

(a) a doctor notifies the employer; and (b) the employee’s current job involves work on or near cooling systems which are located in the workplace and use water; or work on water service systems located in the workplace which are likely to be a source of contamination.

For more guidance on RIDDOR, see www.hse.gov.uk/riddor/index.htm.

19 Those who have, to any extent, control of premises, have a duty under the Notification of Cooling Towers and Evaporative Condensers Regulations 19925 to notify the local authority in writing with details of ‘notifiable devices’. These are cooling towers and evaporative condensers, except when they contain water that is not exposed to the air and the water and electricity supply are not connected. If a tower becomes redundant and decommissioned or dismantled, it should also be notified. Although the requirement is to notify the local authority, the relevant

authority (ie HSE or the local authority) for the premises concerned enforces the Regulations. Notification forms are available from the local authority or local environmental health department. The main purpose of these Regulations is to help investigate outbreaks.

20 The Safety Representatives and Safety Committees Regulations 1977 and the Health and Safety (Consultation with Employees) Regulations 19966 require employers to consult trade union safety representatives, other employee representatives, or employees where there are no representatives, about health and safety matters. This includes changes to work that may affect their health and safety at work, arrangements for getting competent help, information on the risks and controls, and planning of health and safety training.

21 You can find more information in the HSE leaflet Legionnaires’ disease: A brief guide for dutyholders7 and at www.hse.gov.uk/legionnaires/index.htm.

Scope and application

Guidance 22 This Approved Code of Practice applies to the control of legionella bacteria, in any undertaking involving a work activity managed by you or on your behalf. It applies to premises controlled in connection with a trade, business or other undertaking where water is used or stored; and where there is a means of creating and transmitting water droplets (aerosols) which may be inhaled, causing a reasonably foreseeable risk of exposure to legionella bacteria.

23 There is a reasonably foreseeable risk of exposure to legionella bacteria in:

(a) cooling systems with cooling towers, evaporative condensers or dry/wet cooling systems; (b) hot and cold water systems; (c) spa pools (see paragraph 24); (d) other plant and systems containing water that can create and increase the risk from legionella during operation or when being maintained (see paragraphs 13, 14 and 27).

24 These systems present a risk of exposure to legionella bacteria. There is further technical guidance on these systems in Part 1: Evaporative cooling systems; Part 2: Hot and cold water systems and Part 3: Other risk systems at www.hse.gov.uk/pubns/books/hsg274.htm. Specific guidance on managing spa pools is available at www.hse.gov.uk/legionnaires/spa-pools.htm.

25 All systems require a risk assessment, however not all systems will require elaborate control measures. A simple risk assessment may show that the risks are low and being properly managed to comply with the law. In such cases, you may not need to take further action, but it is important to review your assessment regularly in case of any changes in your system, and specifically if there is reason to suspect it is no longer valid. There is more information specifically for those in control of premises, eg landlords, in Part 2: Hot and cold water systems at www.hse.gov.uk/pubns/books/hsg274.htm and at www.hse.gov.uk/legionnaires/what-you-must-do.htm.

Information box

An example of a low risk situation may be found:

(a) in a small building without individuals especially ‘at risk’ from legionella bacteria; (b) where daily water usage is inevitable and sufficient to turn over the entire system; (c) where cold water is directly from a wholesome mains supply (no stored water tanks); (d) where hot water is fed from instantaneous heaters or low volume water heaters (supplying outlets at 50 °C); (e) where the only outlets are toilets and wash hand basins (no showers).

Guidance 26 A water system includes all plant/equipment and components associated with that system, eg all