Offices used to be low risk for legionella because the water was used all day, every day. Hybrid working has changed that. Floors sit half empty, showers go unused for weeks, and water stands in the pipes. A legionella risk assessment shows whether your building’s water system is still under control.
Your duty as an employer
Employers have a duty to assess and control risks to health under the Safety, Health and Welfare at Work Act 2005, and legionella is covered by the Biological Agents Regulations 2013. The Health and Safety Authority asks employers to carry out a written legionella risk assessment, record the findings and review it. National guidelines from the Health Protection Surveillance Centre recommend a review at least once a year.
Why offices are higher risk than they were
- Low occupancy: fewer people means less water drawn through the system.
- Quiet days: Mondays and Fridays with almost nobody in.
- Unused facilities: cyclists’ showers, disabled toilets, kitchenettes on empty floors.
- Oversized storage: tanks sized for full occupancy now hold water for much longer.
- Vacant floors: space handed back or awaiting a new tenant, still connected to the system.
Legionella grows best in water between 20°C and 45°C. Standing water in a warm ceiling void or riser drifts into that range.
What the assessment covers
- Cold water storage tanks: size, condition, temperature and turnover.
- Water heaters and hot water temperatures.
- Showers, taps and any outlet that creates spray.
- Little-used outlets and vacant areas.
- Dead legs left by fit-outs and alterations.
- Other systems: cooling towers, humidifiers, water features and irrigation.
- Who does the routine checks and how they are recorded.
Tenant or landlord?
In a multi-tenant building the landlord usually controls the tanks, risers and plant, and each tenant controls the outlets on their own floor. Ask your landlord for a copy of the building’s legionella risk assessment, and make sure someone is flushing the outlets on your floor when they are not in use.
Practical steps between assessments
- Flush little-used outlets on a set schedule, typically weekly, and record it.
- Check and record hot and cold water temperatures.
- Clean and descale shower heads.
- Tell whoever manages the system when a floor is vacated or reoccupied.
Safer Solutions provides legionella risk assessments and sampling in Dublin for offices and commercial buildings across the city and county. Call 086 275 9728, email info@safersolutions.ie or request a quote.