Who Is the Responsible Person for Legionella Control?
The Responsible Person for Legionella control is the competent individual appointed by the dutyholder to take day-to-day responsibility for managing the Legionella risk in a building's water systems. The dutyholder, usually the employer or the person in control of the premises, keeps overall legal responsibility, but the Responsible Person makes sure the control scheme is actually carried out.
The role is set out in the Health and Safety Executive's Approved Code of Practice (ACOP) L8 and its supporting technical guidance, HSG274. This article explains how the role differs from the dutyholder, what it involves, who should be appointed and the gaps that most often come to light.
The dutyholder and the Responsible Person: what is the difference?
Under the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations 2002 (COSHH), Legionella bacteria are a hazardous substance, and the duty to assess and control the risk falls on the dutyholder. ACOP L8 identifies the dutyholder as:
the employer, where the risk arises from their work activities or premises under their control
a self-employed person where there is a risk from their undertaking to themselves or others
the person in control of the premises or water systems in connection with their business, such as a landlord or managing agent
The dutyholder cannot hand that legal duty to someone else. What they can do, and are expected to do, is appoint one or more competent people to manage the risk on their behalf. ACOP L8 calls this person the responsible person: someone with day-to-day responsibility for controlling any risk from Legionella bacteria identified in the risk assessment.
Appointing a Responsible Person, or bringing in a third party such as a managing agent, does not transfer that legal responsibility. ACOP L8 guidance is clear that employing contractors or consultants does not absolve the dutyholder of their duties.
What does the Responsible Person for Legionella do?
The Responsible Person's job is to make sure the risks identified in the Legionella risk assessment are controlled, and that the control measures stay effective over time. Typical responsibilities include:
making sure a suitable and sufficient risk assessment is in place and is reviewed when circumstances change
implementing and managing the written control scheme, including who carries out each task and how often
arranging routine checks such as temperature monitoring, flushing of little-used outlets and inspections, in line with HSG274
reviewing monitoring results and making sure action is taken when they fall outside control parameters
overseeing contractors and checking that their work meets the required standard
making sure records are complete, accurate and kept for the required period
reporting significant problems and resource needs to the dutyholder and senior management
HSE's guidance on managing the risk makes the point that where a contractor carries out water treatment or monitoring, it is still the Responsible Person's job to make sure the work is done to the required standard. Receiving a service report is not the same as checking it.
Who should be appointed?
ACOP L8 does not prescribe a job title or a specific qualification. Instead, the person appointed should have sufficient authority, competence and knowledge of the installation to make sure all operational procedures are carried out effectively and on time. HSE confirms the Responsible Person can be:
the dutyholder themselves, if they are self-employed or a partner and are competent
one or more employees
someone from outside the organisation
In most organisations the role sits with a facilities, estates or site manager who already has authority over building maintenance. That authority matters: a Responsible Person who cannot approve remedial work or instruct contractors will struggle to act on what the monitoring shows.
Where the role is shared, for example across several sites or shifts, each person's responsibilities should be defined in writing so that everyone knows what they are responsible for and how their part fits into the overall management of the risk.
Deputies and cover
ACOP L8 guidance expects arrangements to be in place so that the Responsible Person, or an authorised deputy, can be contacted at all times. Name the deputy in the written control scheme, make sure they have been trained, and give them access to the records and contractor contacts they will need.
What competence looks like for a Responsible Person
In ACOP L8, competence means having the ability, experience, instruction, information, training and resources to carry out the role. For a Responsible Person, that usually means understanding:
how and where Legionella bacteria grow, and which parts of their own water systems present a risk
the significant findings of their site's risk assessment
the control measures in the written scheme, and why each one matters
what monitoring results should look like, and what to do when they are out of range
when to seek specialist advice
There is no single mandatory course, but formal Responsible Person training is the usual way to build and evidence competence. It should cover the legal framework, HSG274 Part 2 for hot and cold water systems (and Part 1 where cooling towers are present) and the practical management of the site's own systems. Keep training records as evidence.
Common gaps in Responsible Person arrangements
The same problems appear again and again when Responsible Person arrangements are reviewed:
the Responsible Person is named in the risk assessment but was never told, or has since left the organisation
the appointed person has had no training, or their training is many years old
no deputy is named, so monitoring stops during holidays or sickness
the Responsible Person lacks the authority or budget to complete remedial actions
contractor reports are filed without being reviewed, so out-of-range results go unnoticed
the written control scheme no longer reflects what actually happens on site
Several of these link directly to risk assessment review. ACOP L8 guidance lists a change in key personnel as one of the reasons to review the risk assessment. When a Responsible Person leaves or changes role, the appointment, the written scheme and the risk assessment should all be checked. A BS 8580-1 compliant risk assessment should clearly record who holds these responsibilities.
Recording the appointment
HSE's guidance on keeping records says records should include the people responsible for conducting the risk assessment and for managing and implementing the written scheme. ACOP L8 guidance also expects the names and positions of those responsible, and their deputies, to be recorded.
Records of monitoring, inspections, tests and checks should be kept for at least five years. Other records should be kept for as long as they remain current and for at least two years afterwards. They are usually the first thing an inspector or auditor asks to see.
Key points
The dutyholder keeps legal responsibility for Legionella control and cannot delegate it.
The Responsible Person is appointed to manage the risk day to day and should have sufficient authority, competence and knowledge of the installation.
The Responsible Person can be the dutyholder, an employee or someone external, but contractors do not remove the dutyholder's duties.
Name a trained deputy so that the Responsible Person, or their deputy, can be contacted at all times.
A change of Responsible Person should trigger a review of the risk assessment and written control scheme.
Record the names and positions of those responsible, and keep monitoring records for at least five years.
Frequently asked questions
Is it a legal requirement to appoint a Responsible Person for Legionella?
ACOP L8 says the dutyholder should appoint a competent person or persons to take day-to-day responsibility for controlling the risk. ACOP L8 has special legal status: if you do not follow it, you would need to show that you have complied with the law in some other way that is equally effective. In practice, appointing a Responsible Person is expected.
Can the Responsible Person be an external contractor?
Yes. HSE confirms the Responsible Person can be someone from outside the organisation. The dutyholder should take reasonable steps to make sure that person is competent, and still keeps overall legal responsibility. Many organisations appoint an internal Responsible Person and use contractors for specialist tasks such as risk assessments and sampling.
Do healthcare premises use different roles?
Yes. In healthcare premises, HTM 04-01: Safe water in healthcare premises sets out a more detailed management structure. This includes a Water Safety Group and an independent Authorising Engineer (Water) alongside the Responsible Person (Water). The principles in ACOP L8 still apply.
How often should a Responsible Person be retrained?
ACOP L8 does not set a fixed refresher interval. Many organisations refresh Responsible Person training every few years, and sooner when systems, guidance or the person's responsibilities change. Keep evidence of the training completed.
References and further reading
HSE, L8 (fourth edition): Legionnaires' disease. The control of legionella bacteria in water systems
HSE, HSG274: Legionnaires' disease technical guidance, Parts 1 to 3
The Control of Substances Hazardous to Health Regulations 2002
The Responsible Person is where Legionella control succeeds or fails in practice. With the right person appointed, trained, supported by a named deputy and backed by clear records, a dutyholder can be confident the written scheme is being followed and that problems will be spotted and dealt with quickly.
Andrew Arnold
Co‑founder & Director
Andrew has over 20 years' experience in Legionella management and control. As a senior member of the Water Management Society and educated to masters level Andrew has extensive experience in legionella risk assessment of numerous systems and sectors.