The risk of Legionella following the COVID-19 pandemic

Following the Government’s announcement last week, businesses are considering how a return to work might look. With many premises being left unoccupied (or minimally occupied) during the lockdown, both Public Health England and the Health and Safety Executive have warned of the increased risks of Legionella growth in stagnant and unused water systems.

Legionella – employers’ obligations

The Health and Safety at Work Act 1974 places a duty on employers to ensure the health, safety and welfare of their employees so far as is reasonably practicable. This includes the provision and maintenance of systems and facilities that are safe and do not cause risks to the health of employees.

Employers are also required to control substances that are hazardous to health, including germs that cause diseases (such as Legionella bacteria which can cause Legionnaires’ disease) in accordance with the Control of Substances Hazardous to Health Regulations 2002 (‘COSHH’). COSHH requires that employers prevent or reduce exposure to hazardous substances by assessing the risks and implementing appropriate control measures.

The Health and Safety Executive’s guidance states that any water system that has the ‘right’ environmental conditions could potentially be a source for Legionella bacteria. As such, a water hygiene risk assessment should be carried out by employers (or a contractor appointed by the person in control of the premises) for all water systems. This assessment should be regularly reviewed.

What are the risks during/following the Covid-19 pandemic?

Following the Government’s measures to reduce the spread of Covid-19, a significant proportion of the UK population has been required to stay at home, leaving many buildings unoccupied for weeks, possibly months.

Ensuring that water does not stagnate in the system is crucial to reducing the risk of Legionella. There is, therefore, an increased likelihood of Legionella bacteria building up in the water systems of buildings left unoccupied (or with minimal occupancy).

Next steps

If your premises have been unoccupied or minimally occupied during the crisis, there may be an increased health risk to occupants upon their return.  

It is important not to assume that because the water system on your premises was previously low risk, it will remain so after a period of disuse. Buildings should not be re-occupied until duty-holders have taken all reasonably practicable precautions to control any water hygiene-related risks that may have arisen during the lockdown. Businesses should promptly review their current water hygiene risk assessment to reflect current usage and consider whether there is a heightened risk of Legionella as a result of the lockdown.

Where risk is identified, appropriate next steps (such as interim control measures or water testing and/or treatments) should be determined and actioned in a timely manner, and in any event, prior to the premises being re-occupied.

For further guidance from the Health and Safety Executive, please see here.

For more information

Should you require any advice regarding employers’ health and safety obligations, please contact Lorna Kenyon from our Regulatory team.

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