HSE invites water management specialists plus suppliers and users of surface treatment equipment to a Legionella Awareness seminar, Birmingham, 27 March 2009

Date:

13 January 2009

Release No:

HSE/WM/437/2009

The Health and Safety Executive (HSE), is holding a Legionella Awareness Seminar, at 10.00 am, in Birmingham, on 27th March, 2009 to communicate information about risks from Legionella bacteria in aqueous surface pre-treatment processes, following two cases of Legionnaires' disease contracted from this type of plant.

HSE wants to raise awareness of this newly confirmed problem, issues facing the industries involved and to offer practical advice on minimising risk from the types of wash processes typically found in the finishing of automotive components, motors, panels and white goods.

HSE's action follows a recent investigation carried out after two workers at a large engineering company became seriously ill. It was discovered that they had contracted Legionnaires' disease from a previously unidentified source: contaminated water in a conveyorised tunnel aqueous washing process.

Such equipment typically consists of a number of wash, rinse and surface treatment stations containing aqueous solutions sprayed through banks of nozzles. Metal components travel through the washer, suspended from an overhead monorail, before being dried and painted.

In the installation where the problem was identified, rinse water was stored in tanks at the side of the tunnel, notionally at ambient temperature. However, carry-over of heated wash solution from the cleaning process caused the rinse water temperature to rise to between 25 and 45°C. This water temperature range, together with rust and scale build up in the tanks, provided conditions under which the legionella bacteria could proliferate. As the contaminated wash solution was sprayed onto the components, some of the contaminated spray mist leaked out of the tunnel where it could be inhaled by nearby workers. For plant fitted with extraction an additional risk exists, as the same vapour discharged outside could potentially expose the public to airborne bacteria.

HSE Principal Inspector Peter Woolgar advised: "A legionella risk assessment needs to cover all water systems on sites where water is sprayed or water mists generated, particularly for companies with this sort of plant. Unless there is someone with appropriate expertise on site, specialist advice should be sought.

"Where a legionella risk is identified, microbiological sampling will usually be necessary to find out the level of contamination. Then a regime for draining-down, cleaning, disinfecting and monitoring the system should be put in place.

"Manufacturers and suppliers, as well as users and water treatment specialists, should not underestimate the risk of this type of equipment giving rise to this life-threatening disease and should ensure all the usual precautions against legionella are in place."

Further information on Legionnaires' disease is available on the HSE website http://www.hse.gov.uk/legionnaires/
and the Health Protection Agency's website:
http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoListName/Page/1191942128205?p=1191942128205

Notes to editors

1. Legionnaires' disease is caused by bacteria which are found naturally in environmental water sources.
2. The ideal temperature for bacterium to multiply is between 20 and 45°C and it thrives in areas where there are high concentrations of rust, algae, limescale and organic particles.
3. Infection occurs when droplets of contaminated water are inhaled.
4. Men over the age of 45, smokers and anybody whose immune system is suppressed are in the high risk category.
5. Legionnaires' disease can be fatal.

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Issued on behalf of the Health and Safety Executive by COI News and PR West Midlands.