Do small businesses need to control legionella?

The duty is real, even for small sites

Legionella bacteria cause Legionnaires’ disease, a serious and sometimes fatal form of pneumonia. They grow in water systems, especially where water sits still and sits warm.

If you are an employer or you control premises with a water system, you have a legal duty to assess and control that risk. It comes from the Health and Safety at Work etc. Act 1974 and the COSHH Regulations 2002, and the practical detail is in the HSE’s Approved Code of Practice L8 and the technical guidance HSG274. There is no small-business exemption: even a cafe, salon or small office with hot and cold taps and a water heater has the duty.

For most premises, it is simple

The reassuring part is that for a simple, low-risk system the duty is modest. You are not usually looking at expensive water treatment. The core is:

• a risk assessment of your water system, identifying where water could stagnate or sit at a risky temperature,
• temperature control: cold water kept below 20C, hot water stored at 60C and reaching at least 50C at the outlet within a minute,
• flushing outlets that are used infrequently (a rarely-used tap or shower) on a regular basis so water does not stagnate,
• descaling and cleaning shower heads and taps, since scale and biofilm harbour bacteria, and
• a record of the checks.

Legionella thrives between about 20C and 45C, so the whole strategy is to keep water either properly cold or properly hot, and moving.

Why the record matters

The risk assessment and the monitoring record are what turn “we keep an eye on it” into something an HSE inspector, or your insurer, will accept. If there were ever a confirmed case linked to your premises, the first question is whether you assessed and managed the risk, and the logbook is the answer. A simple legionella monitoring logbook keeps the temperature checks, flushing and cleaning in one place, so the duty is met without it becoming a burden.