HSE ACoP L8 Explained: What the Legionella Code of Practice Requires

Ask anyone in water hygiene what the rules are and they will say “L8”. It is HSE’s Approved Code of Practice on the control of legionella in water systems, and while it is not itself the law, it has a legal status that makes ignoring it very unwise. Here is what it is, what it requires, and how the technical guidance fits around it.

What an Approved Code of Practice is

An ACoP is guidance approved by HSE with the consent of the Secretary of State. It is not law, but under the Health and Safety at Work Act it has a special status: if you are prosecuted for a breach and it is proved you did not follow the relevant ACoP, you will be found at fault unless you can show you complied with the law in some other way. In practice, L8 is the standard duty holders are judged against.

General information, not legal advice.

The duties L8 sets out

1. Identify and assess sources of risk. A risk assessment by a competent person covering where legionella could grow and spread and who could be exposed.
2. Manage the risk. Appoint a responsible person with the authority, competence and knowledge to manage the control scheme.
3. Prevent or control the risk. Where possible avoid conditions legionella needs; otherwise control them through a written scheme: temperature control, flushing, cleaning, disinfection, monitoring.
4. Keep records. Of the assessment, the scheme, who is responsible, the monitoring results and actions taken, retained for at least five years.
5. Review. Regularly and on change, as our guide to review frequency explains.

Duty holder and responsible person

L8 distinguishes the duty holder (the employer or person in control of the premises, who carries the legal responsibility) from the responsible person they appoint to manage the risk day to day. The responsible person must be competent, which may mean training for an in-house manager or contracting a specialist. Appointing someone does not transfer the duty holder’s liability.

HSG274: the technical guidance

HSG274 sits beneath L8 and gives the practical detail in three parts: Part 1 on evaporative cooling systems, Part 2 on hot and cold water systems, and Part 3 on other risk systems such as spa pools. Part 2 is the one most commercial premises need: it sets out the temperature targets (hot water stored at 60°C and distributed at 50°C or above, cold water below 20°C), the flushing and monitoring routines, and the inspection intervals that a written scheme is built on.

What it looks like in practice

For a typical office: a competent assessment with a schematic; a named responsible person; a written scheme with monthly temperature checks at sentinel outlets, weekly flushing of little-used outlets, quarterly shower-head cleaning and annual tank inspection; a logbook; and a review every two years or on change. Our guide to the written scheme sets this out.

Getting compliant

ComSurv matches you with competent legionella risk assessors who work to L8 and HSG274, for assessments, written schemes and monitoring, with no-obligation quotes.

Sources & further reading

• HSE ACoP L8: Legionnaires’ disease, the control of legionella bacteria in water systems — the Approved Code of Practice itself
• HSE HSG274: technical guidance — the technical guidance supporting L8
• HSE: Legionnaires’ disease — HSE’s overview

External links open in a new tab. ComSurv is a matching service, not a firm of surveyors, and is not affiliated with these organisations. This article is general information, not legal, surveying or valuation advice; take advice on your specific situation.