Closed Business Premises and Legionnaires’ Disease

Important Message to Business Operators about Closed Business Premises and Legionnaires’ Disease (Legionellosis)

As the Government is now advising home working due to the COVID crisis and many business premises have been temporarily wholly or partly shut down, it is important to remind you of the Legionella risks in vacant properties when water is allowed to stagnate within the hot and cold water systems. Closure of buildings, parts of buildings or their restricted use, can increase the risk for Legionella growth. These circumstances, especially during warm weather can allow Legionella bacteria to grow to harmful levels that, when the building is re-occupied and water systems are re-used, could lead to someone contracting Legionnaires’ Disease if you do not take action to prevent this. 

Legionnaires’ Disease is a type of pneumonia which can cause serious illness in persons who are susceptible, such as those over 50 years of age, smokers and those with underlying health conditions. In Europe, just under 1 in 10 of those acquiring the disease die. The disease is caused by Legionella bacteria in the water supply being breathed into the lungs.

The risk is increased if you use any aerosol forming equipment such as showers, hoses, misters etc. as the water droplets produced can be the right size to be breathed into the lungs and lead to the development of the disease. 

As a business operator, you have legal obligations to maintain the water systems in your premises to prevent growth of Legionella bacteria. 

As a general principle, outlets on hot and cold water systems should be used at least once a week to maintain a degree of water flow and to minimise the chances of stagnation. To manage the risks during non-occupancy, consideration should be given to implementing a suitable flushing regime or other measures such as draining the system if it is to remain vacant for long periods. Links to relevant and more detailed guidance can be found below.

Guidance has been produced by the European Society for Clinical Microbiology and Infectious disease on managing Legionella in building water systems during the COVID-19 pandemic

In addition, consideration is required of other water systems that are no longer in use, such as leisure, sports and swimming and spa pool facilities. We suggest that for these facilities, you should follow the procedures described in the Pool Water Treatment Advisory Group Code of Practice  

Guidance issued by the Health and Safety Executive for landlords can also be applied to workplaces which become less occupied.

If you require any further information about the above, you can contact Environmental Health 

Last updated Wednesday, 30th September 2020