All About Legionnaires' Disease

Recently in England and Wales, there were approximately 540 Legionnaires’ disease cases with a mortality rate of 8%. In the more susceptible groups this rate is thought to be in excess of 40%. Most cases were in males over 40 years old. Some 60% of cases are regarded as community acquired, as opposed to hospital acquired (approx 1%), and travel associated (30% abroad, 10% UK), according to data from the National Surveillance Scheme for Legionnaires’ Disease.

In the UK, Legionnaires’ disease has been most commonly associated with hot and cold water systems in large buildings, such as hospitals and hotels, and infections are usually sporadic as opposed to outbreaks with large numbers of people affected. Historically outbreaks have been associated with wet evaporative condensers (cooling towers), but increased controls have reduced incidences.

Well publicised examples of Legionellosis this year include an outbreak on the Black Watch cruise liner which affected 7 elderly people; 80 prisoners were evacuated from a Kent jail as a precautionary measure; and in a Sunderland health club up to 115 people may have been affected with Legionella-like symptoms. Household plumbing systems have also been implicated in sporadic cases of Legionnaires’ disease. In one UK study legionellae were isolated from approximately 15 % of the homes of affected patients in comparison with around 5 % of homes in a control group.

For more informtion on outbreaks and Legionella incidents see the following LINK

What is Legionella?

Legionella is a particularly aggressive form of bacteria that when inhaled in contaminated water droplets rapidly multiplies and produces a severe and potentially fatal form of pneumonia. Legionnaires' Disease mainly affects adults, with men being more at risk than women. The greatest incidence of disease is in men over 40 years of age who also smoke. Persons who are immuno-compromised or suffering from respiratory disorders are also at higher risk.

There are 300-400 identified Legionnaires' Disease cases reported each year in the United Kingdom. There are many more cases that go undetected, estimated figures would suggest 7-8,000.

What is a Risk Assessment?

A Risk Assessment is a survey conducted by or on behalf of a person who has a statutory responsibility or their nominated responsible person who is in control of premises and/or systems that have a suspected potential for the generation of legionella bacteria.

Where does a Risk Assessment for Legionella apply?

Where there is a trade, business or other under taking where water is used or stored.
The assessment must give details in a way that both technical and non-technical persons can understand.

It must contain:

• Site details.
• Site personnel details.
• Clearly identify the areas assessed.
• Management and Responsible persons clearly identified.
• Risk Rating and the mechanics to how it was reached.
• Show defects with supporting evidence and a programme of rectification.
• Show defects in the monitoring and maintenance procedures.
• Simple schematics of the systems identified.
• LCA company certification.
• Clearly explain each section of the assessment so as the reader will understand the results given.

The Assessment should:

Report on the level of risk of work activities or water systems on the premises that may promote the risk of exposure to legionella bacteria.
Where a potential risk is identified, recommend measures to prevent/minimise that risk.
If it is not reasonably practicable to eliminate the risk, a plan of detailed action to control the risk is recommended.

Why do I need a Risk Assessment?

The establishment owner / employer in charge of the premises has responsibility for the welfare of the general public and / or the people who use the premises.

L8 (8th January 2001) The Approved Code of Practice (ACOP) entitled Legionnaires' Disease: the control of legionella bacteria in water systems, gives practical advice on the requirements of the HSWA and COSHH concerning the risk from exposure to legionella bacteria. In order to comply with the requirements of the HSWA and COSHH, a risk assessment is needed where there is a foreseeable risk.

Any infringement of primary or secondary legislation is a criminal offence. Fines of up to £5,000 may be given in a Magistrates' Court. Unlimited fines or imprisonment may be given in a Crown Court.
An Approved Code of Practice (ACOP) is a form of guidance, therefore failure to follow an ACOP is not a criminal offence. BUT failure to follow an ACOP can be used in evidence against a defendant and the defendant may have to prove that his standards are better or equal to those in the ACOP.

So the current legislation and guidance is now:
The Health & Safety at Work etc. Act 1974
Control of Substances Hazardous to Health Regulations 1988
Approved Code of Practice L8 (January 2001)

Where does legionella naturally occur?

In hot and cold water systems.
In systems with cooling towers.
In systems incorporating evaporative condensers.
In systems containing water which is likely to exceed 20°C and may release a spray or aerosol.

What type of place is at risk?

Any environment where a number of people come together (particularly the general public)and where water is used or stored i.e. Offices, Hospitals, Nursing Homes, Day Centres, Sheltered Housing Supermarkets, Schools, Factories, Government buildings, Libraries, Leisure complexes, Hotels, etc.

What is the first step in the control of Legionella?

You must have a full and proper RISK ASSESSMENT. This is the cornerstone of controlling the bacteria.
Identify and assess the risks
Devise a scheme for controlling the risk
Manage the risk, election and training of competent personnel
Keep records for at least five years.

Can I do it?

Yes. However, in conducting the assessment, the person who draws up and implements precautionary measures should have such ability, experience, instruction, information, training and resources to enable them to carry out their tasks competently and safely. For these reasons it is typical to employ a specialist in this field of work. Reference to this is on page 8 and 9 of the ACOP L8

If I don't do it, who do I employ to do it for me?

A contractor or consultant does not absolve the duty holder of the responsibility for ensuring that control procedures are carried out to the standard required to prevent the proliferation of legionella bacteria. It is therefore very important to ensure the contractor or consultant is qualified and competent. A way of checking the level of service, which should be expected from a service provider, can be found in the Legionella Control Association (LCA) developed jointly by the "Water Management Society" and the "British Association for Chemical Specialities" (WMS/BACS). The LCA does not have any legal status under the H&S law, but should help occupiers choose a service provider to help them control the risks from legionella bacteria

Written by Simon French MWM Soc Dip IHF Exec Dip Man AIOSH AIFL
L8 "Legionnaires' Disease - The control of legionella bacteria in water systems" used as reference