Legionnaires’ Disease – Managing the Risks

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With a rapidly growing global population, the problem of accommodating such numbers is also increasing every day. In the UK business and property owners, employers and those people who manage premises are responsible for managing the risks to the occupants of buildings, including those risks presented by Legionnaires’ disease. This all needs to be done in accordance with various laws including the Health and Safety at Work etc. Act 1974, COSHH, other legislation, and the Health and Safety Executives ACOP L8.

It’s important that those with responsibility ensure that the rules and regulations associated with the control and management of Legionella bacteria and Legionnaires’ disease in the workplace are properly managed.

What Is Legionnaires’ Disease?

The condition known as Legionnaires’ disease is a serious infection of the lungs that shows itself as a form of pneumonia. It is caused by Legionella bacteria and can be very harmful, sometimes fatal in around 10 to 15 percent of cases.

The disease is caused by inhaling small droplets of bacteria contaminated water that are suspended in the air, called an aerosol. The disease cannot be transferred from person to person or contracted by drinking contaminated water. Some in the population are more susceptible to the disease than others including people who are already ill, those with weak immune systems, older people especially men, and heavy drinkers and smokers.

Legionella bacteria are found in environment natural environments including ponds, lakes, rivers and sometimes soil. The bacteria can also colonise man-made water systems used in buildings.

The bacteria will grow at temperatures between 20 and 45°C under normal conditions and can survive at low temperatures. The UK’s Health and Safety Executive (HSE) recommends that Legionella bacteria can be killed in domestic hot water systems if the temperature of the water is raised above 60°C.

What are a Duty Holders Responsibilities?

The duty holder, meaning a business owner, landlord or someone in control of a building must be fully aware of their responsibilities under the law, especially if they are to protect the health and safety of the occupants of the building, visitors and other people who may be exposed to risk from their work activity.

The duty holder and their appointed responsible person must ensure risks from Legionella bacteria and Legionnaires’ disease are effectively assessed, managed and controlled to keep the water systems safe. The responsible person should record all risks, precautions that are in place and actions taken – this is essential.

A good legionella risk assessment will help to safeguard people whether they are guests or employees. For example, your premises should have a properly managed water system which can provide safe water on a daily basis. Things you can do to help include ensuring that the water is kept at the correct temperature – hot water hot and cold water cold – all the water tanks should be correctly sized, insulated and covered with a tight-fitting lid.

You should keep your water systems clean and also consider removing all the unnecessary pipe work, unused showers and other water outlets – this can also help in minimise the risk of exposure to this bacterium.

In the UK the consequences of ignoring your obligations under the Health and Safety at Work Act and COSHH regulations can be very serious.

Risk Assessment for Legionnaires’ disease

To start the risk management process it is strongly recommended that you carry out a full Legionella risk assessment of the water systems used in your buildings, premises or place of work.

The responsible person should recognise that a detailed legionella risk assessment will allow them to identify all the systems that use water and assess their risk. The assessment will also look at the management and control procedures that are in place and make recommendations for improvement where this is felt necessary.

The assessment will look at water temperatures to check if cold water is being kept below 20 Degrees Celsius and the hot water is above 50 Degrees Celsius (55 in healthcare). It will also check to see if the water systems are clean and free from nutrients that would allow Legionella and other bacteria to grow. Different nutrients that may be present in water can help the growth of legionella. For example, rust, scale and other natural matter can act as food source for the bacterium.

The risk assessment should also look at whether people who are more at risk from the illness use the building or the local area. For example a senior care home or hospital would pose a greater risk because of the susceptibility of the people using these facilities.

When should the Assessment be Reviewed?

The Legionella risk assessment should ideally be reviewed at least every couple of years, but sooner if there are changes to the use of the building, staffing, to the water systems, if you suspect that the water systems are contaminated or if it causes an outbreak of Legionnaires’ disease.

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