User guide for chemical indicators for wash disinfectors


The chemical indicators are used daily to check the effect of cleaning in dental wash disinfectors. It is the critical parameters such as time, temperature, and contact of water and detergent that are verified.


Make sure the holder is clean and dry.

The chemical indicator is placed in a dedicated holder designed specifically for the type of chemical indicator.

Make sure the indicator is centred in the holder.

The holder is placed in a tray or basket where it must stand upright as shown in the figure below, in the most difficult and challenging places for the machine to clean.

Run the machine on a commonly used cleaning program.

After wash

Remove the indicator from the holder gently and in a safe manner, as it may be warm and residues of the test material can stain.

Make sure that the indicator is completely free of visual residue from the test material. This can be performed against a white background, e.g. white paper.

If the indicator is not 100% free of the test material, the test is failed. Corrective action must be taken to remedy the problem according to the procedure from manufacturer of wash disinfector.

There can be several reasons why the machine does not clean sufficiently:

  • Incorrect setting of time and temperature.
  • Incorrect concentration/dosage of detergent.
  • Low water pressure and/or poor water quality.
  • Wash arm(s)/nozzles may be fully/partially clogged.
  • Rotating wash arm(s) do not rotate.

Consult relevant guidelines from national healthcare authorities for further action.