There are over 40 different types of Legionella bacteria, the most common known as Legionnaires’ Disease.
Legionnaires’ Disease is a potentially fatal, bacterial pneumonia infection that is contracted by breathing in water droplets.

Duties under the Health and Safety at Work etc Act 1974 (HSWA) extend to risks from legionella bacteria, which may arise from work activities. The Management of Health and Safety at Work Regulations (MHSWR) provide a broad framework for controlling health and safety at work. More specifically, the Control of Substances Hazardous to Health Regulations 2002 (COSHH) provide a framework of actions designed to assess, prevent or control the risk from bacteria like Legionella and take suitable precautions. The Approved Code of Practice: Legionnaires’ disease: The control of Legionella bacteria in water systems (L8) contains practical guidance on how to manage and control the risks in your system.

A Legionella Risk Assessment is the legal requirement and should be the starting point of all water management programmes. This should be followed by a monitoring programme to continuously assess the risk from Legionella bacteria.

The Approved Code of Practice requires that Legionella Risk Assessments be updated regularly (every two years at least) or when significant changes occur that may render the current risk assessment invalid. Further to this a regular review should be conducted to ensure the systems are being suitably managed. The control scheme and level of monitoring depends on the water systems and services located on your site. Typically, in a standard office space or building, with a basic domestic water system, a programme of routine temperature checks and 6 monthly and annual inspections will be required including an annual review.

As an employer, or person in control of premises, you must appoint someone competent to help you meet your health and safety duties and to take responsibility for controlling any identified risk from exposure to legionella bacteria. A competent person could be yourself, one of your workers or someone from outside your business.