RR1118 - Legionella control in evaporative cooling systems: underlying causes of breaches in health and safety compliance

Evaporative cooling systems, such as cooling towers and evaporative condensers, are susceptible to colonisation by Legionella bacteria. Previous evidence has demonstrated that they can be responsible for sporadic outbreaks of infection, ranging in scale both in terms of numbers infected and severity. When outbreaks occur, they frequently infect members of the public rather than workers and, in many cases, are a major public health concern.

HSE inspected 1,906 premises with evaporative cooling systems between 1st April 2013 and 31st August 2014. While the majority of sites required no enforcement, material breaches were found at 625 sites (33% of those inspected), including 409 Improvement Notices (INs) and 12 Prohibition Notices (PNs) served at 229 sites (12.0% of those inspected).

Underlying causes of breaches of health and safety compliance were analysed. The main ones were lack of training, failure to maintain the cleanliness of cooling towers and the water within them, absence of, or inadequate, risk assessments, and absence of, or insufficiently detailed, written control schemes. Further analysis looked into the reasons why cooling towers were not cleaned properly.

These results provide a valuable resource which can be used to focus future strategies to improve dutyholder compliance.

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Updated 2021-04-15