Every dental practice in England needs a legionella risk assessment and a written scheme for controlling any risks it finds. CQC’s mythbuster on legionella and waterlines lists this under mandatory requirements, and says experienced and competent people should write these schemes.
The health and safety law behind this applies more widely, but the CQC expectations and HTM 01-05 described here are for practices in England. Your competent person should advise on your actual building.
Why a legionella risk assessment matters in a dental practice
The Health and Safety Executive (HSE) says that as an employer, or someone in control of premises, you must identify and assess sources of risk, manage them, prevent or control them, and keep the correct records.
HTM 01-05, the decontamination guidance for dental practices in England, says registered managers should make sure water supply, storage and distribution comply with best practice guidance. That means the HSE’s Approved Code of Practice L8 and HTM 04-01.
CQC considers legionella and waterline management when it reviews the safe key question, under Regulation 15: premises and equipment.
Who should carry it out
HTM 01-05 says the risk assessment should be carried out by a competent person. CQC describes a competent person as someone with the necessary skills, knowledge and experience to do this work.
The HSE says you may be competent to carry out the assessment yourself, but if not you should ask someone who is. Most managers without a water hygiene background will want an external assessor, and the registered manager must then implement all the recommendations from the scheme and the risk assessment.
What the risk assessment should include
The HSE’s brief guide for dutyholders says a risk assessment should include:
- management responsibilities, including the name of the competent person
- a description of your system
- any potential risk sources
- controls currently in place
- monitoring, inspection and maintenance procedures
- records of monitoring results, inspections and checks
- a review date
HTM 01-05 adds that the assessment should identify problems such as excess storage capacity, temperature distribution problems, low water usage and inappropriate materials.
What goes in the written scheme
A written scheme for legionella in a dental practice sets out how you control the risks that the assessment finds. The L8 code says it should include, where appropriate:
- an up-to-date plan of the water system, for which a schematic diagram is sufficient
- how the system is operated correctly and safely
- the precautions to take
- the checks to carry out, and how often
- the remedial action to take if the scheme is not working
HTM 01-05 also asks for an operational plan for each site, including step-by-step instructions to operate and shut down the water systems and a schedule of possible emergencies that cause loss of water supply.
Legionella testing in dental practices
Most routine work is temperature checking. CQC says how often you test the water for legionella and the temperature of the system depends on the system, its components and the outcome of the risk assessment. So your scheme sets the schedule, and it should name the sentinel outlets, which are the taps used as regular test points. The HSE’s hot and cold water guidance gives these general reference points:
| Check | HSE reference point |
|---|---|
| Cold water at sentinel outlets, monthly | Below 20°C after running for 2 minutes |
| Hot water at sentinel outlets, monthly | At least 50°C within 1 minute of running. HSE’s technical guidance and HTM 04-01 give 55°C for healthcare premises, so ask your competent person which figure applies to your practice and write it into your scheme. |
| Hot water stored in a cylinder | At least 60°C |
| Infrequently used outlets | A programme of regular flushing, weekly |
HTM 01-05 likewise says that L8 recommends flushing sporadically used taps once a week, and that the procedure should be documented.
Laboratory sampling for legionella is a separate matter from temperature checks. The HSE’s guidance links sampling to populations assessed as being at risk, carried out periodically as the risk assessment identifies. Ask your competent person whether your practice needs it.
How often to review it
The L8 code says to review the assessment regularly, and specifically when there is reason to believe it may no longer be valid. Changes to the plumbing, to how rooms are used, or a period of closure could all be reasons to look again. Set a review date in the document so nobody has to remember it.
What records to keep
Where you have five or more employees, significant findings must be recorded. Below five, the HSE says you do not have to write them down, although it is useful to. For a dental practice, HTM 01-05 and CQC expect a written assessment and scheme regardless of team size.
The HSE guide says records should cover who is responsible, the significant findings, the written scheme, and the results and dates of inspections, tests and checks. Those records should be kept for as long as they remain current and for at least two years after that. Records of inspections, tests and checks should be kept for at least five years.
How waterlines fit in
Dental unit waterlines need their own management alongside the building’s water system. CQC says all systems need a risk assessment and that you must control legionella within the dental waterline system. We cover the flushing routine in how often dental water lines must be flushed.
Compliance UK can hold your legionella risk assessment review and water temperature checks as recurring checks, on a default schedule that you can change to match your scheme.
Sources
- CQC: Dental mythbuster 5, legionella and dental waterline management
- NHS England: HTM 01-05, decontamination in primary care dental practices
- HSE: Legionnaires’ disease, what you must do
- HSE: Hot and cold water systems, things to consider
- HSE: L8, the control of legionella bacteria in water systems
- HSE: Legionnaires’ disease, a brief guide for dutyholders (INDG458)
Sources checked on 10 November 2026.