Dental surgeries use water in a different way from most buildings. Narrow tubing in dental chairs, handpieces and scalers produces sprays and mists close to patients, and water can sit in those lines overnight and at weekends.
Why dental settings are worth a closer look
- Narrow tubing gives bacteria a large surface to grow on.
- Water sits still when the practice is closed.
- Sprays and mists are produced during treatment.
- Patients may be vulnerable, such as older people or those with weaker immunity.
- Hand wash basins and sinks may be rarely used in some rooms.
Practical steps
- Include dental water lines in your legionella risk assessment, alongside the building’s main water system.
- Follow the manufacturer’s instructions for flushing, disinfection and any water treatment on dental units.
- Flush lines at the start of the day and between patients, as your procedures set out, and keep a record.
- Check taps and sinks in treatment and decontamination rooms, and flush little-used ones.
- Keep records in your legionella logbook.
- Review after changes, such as new equipment or a refit.
Your duties
Under the Safety, Health and Welfare at Work Act 2005, employers must manage risks to health. The HPSC national guidelines for the control of legionellosis in Ireland give practical advice on controlling legionella in water systems.
Where the water risks sit in a dental practice
Dental units use water in a way that few other premises do. Water runs through narrow tubing to handpieces, scalers and the three-in-one syringe, and it is then sprayed into the mouth and air as a fine mist. Narrow lines, long idle periods overnight and at weekends and warm surgery temperatures all suit biofilm, which can harbour bacteria including Legionella. See our guide to biofilm.
- Dental unit waterlines and the way water is supplied to the unit, including any reservoir bottle or cleaning system.
- Little-used outlets in surgeries, sterilisation rooms, staff rooms and toilets.
- The wider building water system, including tanks, hot water cylinders and temperatures.
- Quiet periods, such as holidays and closures. See our reopening checklist.
Typical good practice
- Follow the manufacturer’s instructions for the dental unit, including any disinfection or water treatment system.
- Flush waterlines and outlets as set out in your procedures, particularly at the start of the day and after quiet spells.
- Keep hot and cold temperatures under review and record them. See our logbook guide.
- Have a written scheme of control that covers the building supply and the dental units.
- Agree with your risk assessor whether sampling is appropriate and how often; see how often sampling is typically done.
Professional standards
Dental practices also work to professional and infection-control standards that apply to dental equipment. These sit alongside, not in place of, the water safety duties in the Safety, Health and Welfare at Work Act 2005 and the HPSC National Guidelines for the Control of Legionellosis in Ireland (2009).
We carry out Legionella risk assessments and sampling for practices and healthcare premises in Dublin, Cork, Limerick and Galway. See Dublin or Limerick.
Talk to Safer Solutions
A legionella risk assessment for your practice looks at the whole water system. Call 086 275 9728 or email info@safersolutions.ie for a friendly chat. See how to read a legionella risk assessment report.