Who is the responsible person for legionella?

The responsible person is the named, competent individual appointed to take day-to-day charge of managing legionella risk. Under ACOP L8, the duty holder (the employer, landlord or person in control of the premises) must appoint them, yet appointing one does not pass the legal duty on.

People often use "duty holder" and "responsible person" as if they mean the same thing. They do not, and the difference decides who is accountable if something goes wrong. This page sets out both roles, explains what the responsible person actually does, and what "competent" is expected to mean in practice.

Where the role comes from

The term "responsible person" comes straight from ACOP L8, the Approved Code of Practice that sits under the Health and Safety at Work etc. Act 1974 and the COSHH Regulations. ACOP L8 says the duty holder should appoint a competent person or persons to take day-to-day responsibility for controlling any identified risk from legionella. That appointed person is the responsible person.

It is a management role, not a job title you have to advertise. A facilities manager, a maintenance supervisor, a landlord, a school business manager or an external water treatment specialist can all fill it, provided they have the knowledge and the authority to do the job properly.

Duty holder versus responsible person

The duty holder is whoever holds the legal duty because they run the premises or the undertaking. In a workplace that is usually the employer. For a rented property it is the landlord or managing agent. The duty holder decides that legionella risk must be controlled and provides the resources to control it.

The responsible person is the person the duty holder appoints to make that happen on the ground. They organise the checks, hold the records and chase the problems. Crucially, the appointment shares the workload, not the liability. If controls are neglected, the enforcing authority still looks to the duty holder, whatever the responsible person did or failed to do.

What the responsible person does

The responsibilities are practical and ongoing. In most premises the responsible person is expected to:

• Make sure a suitable and sufficient legionella risk assessment is in place and reviewed when the system or its use changes.
• See that the written scheme of control is drawn up and actually followed, not left in a drawer.
• Oversee routine monitoring: temperature checks, flushing of little-used outlets, tank and calorifier inspections, and any sampling.
• Act on results. An out-of-range temperature or a positive sample needs a recorded response, not a note that gets filed and forgotten. See what to do if legionella is detected.
• Keep the log book up to date so the record shows what was checked, when, by whom and what happened next.
• Manage contractors, checking that anyone brought in to sample, disinfect or service equipment is competent and that their work is recorded.

The responsible person does not have to carry out every check personally. They do have to make sure the checks happen, that the people doing them know what they are doing, and that the paperwork stands up.

What "competent" means

ACOP L8 does not set an exam pass mark. It expects the responsible person to have enough knowledge, training and experience to understand the system and the risk, plus the authority to act on what they find. Competence is proportionate: a small office with a couple of taps and a combi boiler needs far less than a care home with stored hot water, showers and long pipe runs.

In plain terms, a competent responsible person should understand why water is stored hot at 60°C and should reach 50°C at the outlet within a minute, why cold water is kept below 20°C, why the range around 20°C to 45°C encourages growth, and what the monitoring is meant to catch. Recognised training, for example a legionella management or responsible person course, is the usual way to evidence that, though the record of competence matters more than any single certificate. Authority matters just as much: someone who spots a fault but cannot get it fixed is not, in practice, in control of the risk.

Can it be a contractor?

Yes. Many organisations appoint an external water treatment company or consultant as the responsible person, or share the role between an internal manager and a specialist. That is allowed and often sensible where in-house knowledge is thin.

Two cautions. First, using a contractor does not move the legal duty; the duty holder still owns it. Second, the duty holder needs someone in-house who understands what the contractor is doing, can question it and can act between visits. Membership of the Legionella Control Association is a reasonable marker of a competent service provider, but the duty holder still has to manage the relationship.

Deputy cover and keeping the role live

Legionella control is continuous, so the role cannot lapse when one person is on leave or leaves the job. ACOP L8 expects arrangements to cover absence. Name a deputy, make sure they can reach the risk assessment, the written scheme and the log book, and hand over cleanly when people move on. A monitoring regime that stops for three weeks because the only trained person was away is a gap that shows up in the records.

Getting these roles right is the backbone of legionella compliance. The detail sits in HSG274 Part 2 for hot and cold water systems and in ACOP L8, both of which sit under the Health and Safety at Work etc. Act 1974. Reading them alongside your own risk assessment is the surest way to define what your responsible person needs to do and what they need to know.