Controlling the Risk of Legionellosis
Reviewed December 2011
Background
Legionnaires’ disease is a potentially fatal type of pneumonia caused by Legionella bacteria. It is the most well known and serious form of a group of diseases known as legionellosis. People catch Legionnaires’ disease by inhaling small droplets of water suspended in the air, which contain the Legionella pneumophilia bacterium.
IHAG’s client group includes people who are likely to be particularly susceptible, such as anyone over 45, smokers and heavy drinkers, those suffering from chronic respiratory or kidney disease, and those with an impaired immune system.
The bacterium which causes Legionnaires ‘disease is widespread in nature. It can live in hot or cold water systems and storage tanks in residential properties.
Landlords have a legal responsibility to undertake regular risk assessments to identify potential sources of exposure, and take action to prevent or control any identified risk.
1How do people get it?
The agent that causes Legionnaires' disease is a bacterium called Legionella pneumophila. People catch Legionnaires' disease by inhaling small droplets of water suspended in the air, which contain the bacteria.
Certain conditions increase the risk from Legionella:
1.1A suitable temperature for growth, 20 to 45ºC
1.2A source of nutrients for the organism, e.g. sludge, scale, rust, algae, and other organic matter
1.3Away of creating and spreading breathable droplets, e.g. the aerosol created by a cooling tower or spa pool
However, remember that most people exposed to Legionella do not become ill, and Legionnaires' disease does not spread from person to person.
2Where does it come from?
Legionella bacteria are widespread in nature, mainly living in natural water systems, e.g. rivers and ponds. However, the conditions are rarely right for people to catch the disease from these sources.
Outbreaks of the illness occur from exposure to Legionella growing in purpose-built systems where the water is maintained at a temperature high enough to encourage growth, e.g. cooling towers, evaporative condensers, spa pools, and hot water systems used in all sorts of premises (work and domestic).
Most community outbreaks in the UK have been linked to installations such as cooling towers, which can spread droplets of water over a wide area. These are found as part of air-conditioning and industrial cooling systems.
To prevent exposure to the Legionella bacteria, IHAG/landlords they work with, must comply with legislation that requires management, maintenance and treatment to water systems in premises properly. This will include, but not be limited to, appropriate water treatment and cleaning regimes.
3Symptoms
The symptoms of Legionnaires’ disease are similar to those of flu:
3.1High temperature, feverishness and chills
3.2Cough
3.3Muscle pains
3.4Headaches
In severe cases there may also be pneumonia, and occasionally diarrhoea and signs of mental confusion.
4Designated responsible officer
The Housing Services Manager is the designated responsible officer.
5Risk assessments
The risk assessment should consider a variety of factors including:
5.1Hot and cold water temperatures in the houses. Legionella bacteria can multiply ifthe water temperature is between 20 and 45 degrees centigrade.
5.2Any area where water droplets are produced, e.g. shower heads
5.3Whether any staff or clients are particularly susceptible to the bacterium.
5.4Any areas where stagnant water occurs e.g. pipes to appliances no longer used.
5.5Any infrequently used outlets e.g. showers, taps?
5.6The presence of debris in the water systems (e.g. rust, sludge, scale, algae, other organic matter)
5.7Any thermostatic mixing valves that set a favourable outlet temperature for Legionella growth?
A separate risk assessment is carried out on a regular basis for all buildings, including an up-to-date diagram of each hot and cold water system
All staff and clients are aware of the safe and correct operation of water systems.
6Prevention and control
Water temperatures and conditions that favour the growth of legionella and other micro-organisms are avoided by maintaining correct temperatures. Hot water must be stored at a temperature greater than 60ºC, and the temperature at hot water outlets should not fall below 50ºC. The temperature of incoming mains water should be regularly monitored and the temperature at cold water outlets should be less than 20ºC.
6.1Suitable warning notices should be displayed to warn of danger from scalding by hot water.
6.2Areas where water could stagnate in the system are avoided as far as possible, e.g. by removing redundant pipework, keeping pipe lengths as short as possible, and running taps etc in vacant rooms, especially immediately prior to occupation.
6.3The system and the water in it are kept as clean as possible. Water cisterns are kept covered, insulated, clean and free of debris and the use of materials that encourage the growth of legionella is avoided.
6.4Maintenance staff working on the systems are aware of the risks and how to minimise them
6.5Tenants are advised about the risks and the control measures being taken, and about the precautions they can take, such as flushing through showers after a period of non-use.
7Monitoring
7.1Monthly temperature monitoring of mains water, stored hot water and hot and cold water outlets in IHAG office and all IHAG houses
7.2Monthly temperature monitoring of water inlets and outlets of all drinks dispensers
7.3Showerheads cleaned and disinfected every 3 months
7.4Taps and pipe work in rooms not in regular use are flushed regularly.
7.5Annual checks of condition of cold water storage tanks checked.
7.6Annual checks that the plans of the hot and cold water circuits and correct and up-to-date
7.7All checks and monitoring recorded in logbook, and records kept for 5 years.
8Emergency action plan in event a suspected outbreak of Legionellosis
All the following agencies will be contacted by IHAG as a matter of extreme urgency:
8.1landlord of the property
8.2Anglian Water
8.3Ipswich Borough Council Environmental Health Dept. (01473 432000)
8.4Health Protection Agency (01473 329583 – duty line)
8.5Health & Safety Executive
Advice from these agencies should be readily sought and visits and action planned.
9Tenants
All tenants will be contacted as soon as possible, evacuated from the house, and found alternative accommodation.
10House
This should be locked and secured until IHAG is advised as to who and when to allow entry, to deal with the outbreak of Legionella. Re-occupation will only be allowed when permission has been given by the appropriate authorities.
11Tenants and Staff
Tenants and any staff deemed vulnerable due to house visits, will be tested and treated by the appropriate medical authority as soon as possible.
Further Information and guidance
HSE Publication: ACOP - Approved Code of Practice - L8 Legionnaires disease. The control of legionella bacteria in water systems
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