Dental Unit Water Lines

In dental practices, there is a risk of infection from microorganisms in the biofilm that can accumulate in dental unit water lines. Staff should be made aware of this risk and follow procedures to minimise it. Precise details of these procedures will depend on the way water is delivered to the DUWL (e.g. mains feed, via holding tank, using self-contained bottles) and will be informed by manufacturer’s instructions for the dental chair unit.

Irrespective of dental chair unit design, regularly following flushing procedures will reduce the risk of microbial growth. Standard practice is to flush each DUWL for 2-4 minutes at the start and the end of each working day and for 30 seconds between patients. In addition, use of a biocidal product may be recommended by the DUWL manufacturer, which will specify the dose and frequency. Appropriate PPE should always be worn.

Ensure that staff are aware of the risk of accumulation of bacteria in dental unit water lines.

Put together a written procedure for minimising the risk of growth of bacteria in dental unit water lines, that includes:

  • flushing DUWLs at the start and end of each day for 2-4 minutes
  • flushing each DUWL for 30 seconds between patients
  • use of biocide as recommended by the dental chair unit and biocide manufacturers
  • decontamination and overnight storage of water bottles (if appropriate)
  • flushing/draining of DUWLs when unused for significant periods (e.g. holidays, weekends).

Ensure that staff follow the written procedure and keep a daily record of completion.