Argonaut Heating Ltd

LEGIONNAIRES' DISEASE

Legionnaires' disease is a potentially fatal form of pneumonia which can affect anybody. It is caused by the bacterium Legionella pneumophila and related bacteria. It is normally contracted by inhaling legionella bacteria, either in tiny droplets of water (aerosols), or in droplet nuclei (the particles left after the water has evaporated) contaminated with legionella, deep into the lungs.

Cases of Legionnaires' disease have occurred among staff in the workplace (factories, offices, shops and hospitals); visitors (delivery drivers) and members of the public (patients, hotel guests or passers-by).

Legionella bacteria can survive under a wide variety of environmental conditions and have been found in water at temperatures between 6ºC and 60ºC. Water temperatures in the range 20ºC to 45ºC seem to favour growth. The organisms do not appear to multiply below 20ºC and will not survive above 60ºC. They may, however, remain dormant in cool water and multiply only when water temperatures reach a suitable level. Temperatures may also influence virulence; legionella bacteria held at 37ºC have greater virulence than the same legionella bacteria kept at a temperature below 25ºC.

The incubation period is between 2-10 days (usually 3-6 days). Infection with legionella bacteria can be fatal in approximately 12% of reported cases. This rate can be higher in a more susceptible population; for example, immuno-suppressed patients or those with other underlying disease. Certain groups of people are known to be at higher risk of contracting Legionnaires' disease; for example, men appear more susceptible than women, as do those over 45 years of age, smokers, alcoholics, diabetics and those with cancer or chronic respiratory or kidney disease.

As legionella bacteria are commonly encountered in environmental sources they may eventually colonise manufactured water systems and be found in cooling tower systems, hot and cold water systems and other plant which use or store water. To reduce the possibility of creating conditions in which the risk from exposure to legionella bacteria is increased, it is important to control the risk by introducing measures which:

(a) do not allow proliferation of the organisms in the water system; and

(b) reduce, so far as is reasonably practicable, exposure to water droplets and aerosol.

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LEGIONELLA CONTROL

Many outbreaks of Legionnaires' disease, if not all, are because of lack of training, poor management and incorrectly assessed premises. Legionella Control is required wherever there is water used or stored, irrespective of size and usage.

It is a requirement under the Health and Safety Executive Approved Code of Practice (L8) The control of legionella bacteria in water systems that you have a responsibility to comply with the legal requirements for the control of Legionellosis.

If any premises under your ownership or control has hot and cold water systems, then you have a responsibility to ensure that the risk is controlled and minimized at all times.

Where outbreaks have occurred, prosecutions have been taken under the Health & Safety at Work Act 1974, and under the Control of Substances Hazardous to Health Regulations 1988. Therefore compliance is essential. In order to do this, the recommendations of the Approved Code of Practice (L8) will have to be fulfilled.

This Approved Code of Practice applies to the control of legionella bacteria in any undertaking involving a work activity and 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 which may be inhaled, thereby causing a reasonably foreseeable risk of exposure to legionella bacteria.

Experience has shown that cooling towers, evaporative condensers and hot and cold water systems in a wide variety of workplaces present a risk of exposure to legionella bacteria. This includes schools, colleges, universities, hospitals, care homes, nursing homes, surgeries, dental practices, offices, hotels, shops and more.

LEGIONELLA CONTROL - RISK ASSESSMENT

Do I need to have a Risk Assessment?

If you have a water system that heats or cools water with the potential to create an aerosol then you will need a Risk Assessment. Argonaut Heating Ltd offers a full Risk Assessment and Legionella Control advice service.

Risk Assessments are now required for ALL hot and cold water systems in the workplace, including:

• Universities, Colleges & Schools
• Hospitals and medical centres
• Local authorities premises
• Offices
• Housing associations
• Charities
• Hostels
• Landlords in the private renting sector
• Managing agents
• Hotels & Guest houses
• Sports & Leisure Centres
• Caravan and camp sites
• Residential care homes and nursing homes
• Doctors surgeries, dental practices
• Food processing plants
• Shops

Who Controls the spread of Legionnaire's Disease?

To prevent an outbreak of Legionnaire's Disease ALL companies that operate water systems must comply with the regulations. These regulations require them to maintain, check, manage and treat any systems which could possibly cause the spread of Legionella.

A water system includes all plant/equipment and components associated with that system, e.g. all associated pipe-work, pumps, feed tanks, valves, showers, heat exchangers, quench tanks, chillers etc. It is important that the system is considered as a whole and not, for example, the cooling tower in isolation. Deadlegs and parts of the system used intermittently, for example test loops in engineering factories and injection moulding machines, also need to be included as part of the system since they can create particular problems with microbial growth going unnoticed. Once brought back on-line they can cause heavy contamination, which could disrupt the efficacy of the water treatment regime.

The current legislation stipulates the recommended inspection frequencies (weekly, monthly, annually) for the checks which have to be carried out on the various elements of the hot and cold water services

Contact Argonaut Heating Ltd for further information on our specialised Legionella Control services