Dry Vapour Disinfection Validation

Dortek Ltd

Validation is achieved through the incubation of spore strips that have been exposed to the hydrogen peroxide vapour during the disinfection process.  It is normal practice to place the spore strips in areas of the facility thought to be most inaccessible to the vapour (the strips must be retrievable without being compromised).

Hydrogen Peroxide Vapour

Validation spore strips & recovery media

The spore strips are stainless steel, oblong discs inoculated with Geobacillus stearothermophilius and are specifically for use in hydrogen peroxide vapour.  Each strip or disc contains a standard spore population of 106. Geobacillus stearothermophilius is a commonly used indicator organism to verify the efficacy of sterilisation and disinfection procedures and is not harmful to humans.

Spore Test StripTryptic soy broth is used as a recovery media and is placed alongside every spore strip placed in the facility target area prior to the disinfection process.  At the end of the disinfection process the spore strips are aseptically transferred to the recovery media tubes and transported to an incubator. 

Dry Vapour Disinfection Validation

Incubation & validation process

A control strip which has not been subjected to the dry vapour is placed in to recovery media and incubated, with the exposed strips from the facility, at 56°C.  The tubes of media are checked for signs of growth, indicated by a change in colour, at the pre determined intervals for a period of 7 days.  No colour change indicates that the disinfection process was sufficient to achieve the expected parameters and kill the test microorganisms.

The result of each spore strip used is recorded and a detailed report is provided after the 7 day period, however, no change after 1 – 2 days is usually indicative of a successful disinfection process.

Hydrogen peroxide vapour has been shown to bio-deactivate a wide range of micro-organisms including:

  • Endospore-forming bacteria
  • Vegetative bacteria
  • Atypical bacteria
  • Viruses
  • Fungi

During the delivery of the disinfection process Dortek perform “real time humidity reporting” that produces an immediate indication of the success of the process.  The data forms part of a comprehensive report provided to our clients.

Disinfection Statistics

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