Legionnaires' disease, a serious illness caused by the bacteria Legionella pneumophila, This disease is primarily transmitted through aerosols of contaminated hot water (cooling towers, showers, misting systems). This white paper details the regulatory obligations of operators and the monitoring and treatment methods to control this priority biological risk.
Subject
Which installations are affected by the risk of Legionella (cooling towers, domestic hot water systems, spas)? How can a health logbook, a management plan, and a monitoring program be implemented? What are the target values, alert thresholds, and action thresholds? How are mandatory microbiological analyses performed and interpreted? This white paper offers a practical guide for technical services, HSE (Health, Safety, and Environment) professionals, and building managers.
Key points to remember
- Cooling towers (CTs): alert threshold at 1,000 CFU/L; action threshold at 100,000 CFU/L
- A health and safety logbook is mandatory for all establishments with TAR (thermostatic treatment) or domestic hot water (DHW) networks.
- Mandatory Legionella testing: minimum twice a year for TAR (Respiratory Treatment Areas), once a year for ECS (Emergency Care Systems) in healthcare facilities
- Mandatory reporting to the Regional Health Agency (ARS) in the event of exceeding the alert threshold and in the event of a cluster of Legionnaires' disease cases