The publication, Legionnaires’ disease: The control of legionella bacteria in water systems (L8), consolidated the information in HS(G)70 and the Approved Code of Practice (ACoP). The aim was to make it easier to read and understand your duties under the law.

This L8 document gave more advice on the competence and training for staff that are responsible for developing, managing and conducting risk assessments and implementing the controls.

How can the risk of legionellosis be minimised?
In the original guidance that was introduced by the HSE in 1991, it concentrated on reducing the risk by avoiding conditions where legionella bacteria could proliferate and where possible avoiding the unnecessary exposure to aerosols. Where wet cooling processes could not be replaced with dry ones due to expense, it recommended that legionella growth is controlled through alternative means such as chemical dosing of water cooling systems and also ensuring that the water temperatures for domestic services remain outside of the optimum legionella growth range (20 to 45°C).

However, in non-domestic properties where there is a low through put of water, legionella bacteria can become established and reach high numbers, even if you are following good temperature regimes. The guidance reiterates that it is not the presence or absence of legionella in a single sample that is significant but the possibility of rapid growth of the bacteria to potentially hazardous levels.

The most practical way of dealing with legionella is to have a “control of legionellosis management programme” in place. This includes risk assessments, written schemes, monitoring regimes, auditing regimes, essential documentation and regular programme reviews. This is the approach recommended by the HSE.

If you do not have a management programme in place and you are not monitoring and managing your water systems the failure to do so can have some frightening results. With the Corporate Manslaughter legislation on the horizon it is even more critical to ensure that you have an appropriate management system in place to control the risk of legionella within your building and help protect your business from an unnecessary operating risk.

Risk Assessment
A legionella risk assessment involves a thorough analysis of the risks of exposure that is posed by your water systems. A report is provided with recommendations on how deficient areas can be improved as well as an asset register of plant and detailed schematics. It should consider the likelihood of legionella bacteria contaminating and growing in the water systems, of being disseminated in the aerosols or water droplets, and identify who would be at risk of exposure. Without such consideration you don’t have an L8 risk assessment!

It is recommended that an independent consultancy is used for such risk assessments to ensure that there is no biased view. Recommendations should be based purely on what needs to be done to protect everyone who might be at risk.

The guidance recommends that a risk assessment is reviewed every two years or if other information, changes or monitoring indicates control might be lost. With the potential risks to any business you should be reviewing your risk assessment and management processes to ensure that you continue to meet the requirements of L8.

It is better to assess, manage and monitor from behind your desk than be uncertain as to your position or indeed be “court” out!

Article by:
Ingrid Day
Marketing Manager
ems
T: +44 (0)1403 269375
E: info@ems-online.co.uk