VHP Disinfection Quality Assurance

Dortek Ltd

Vaporised Hydrogen Peroxide (VHP) is fast becoming recognised as the ideal method for disinfection of facilities big and small.  There are countless scientific papers informing us that when Hydrogen Peroxide comes in to contact with a growing list of bacteria and viruses it is effective in achieving a minimum 6 log kill.

Vaporised Hydrogen Peroxide

So how can the customer be assured that the VHP was dispersed to all areas of the target area?

We believe that Dortek are currently the only company in the UK able to provide their clients with real time monitoring of the dispersion of vaporised hydrogen peroxide in the target area.

VHP Disinfection Nozzle VHP DisinfectionVHP Disinfection

Our standard practice is to place Temperature/Relative Humidity sensors in tandem with our bio-indicators around the target facility at different levels and in areas thought to be most difficult for the vapour to access.  Each sensor is individually identifiable and sends a reading every 10 seconds to a data collection unit which then relays the readings to a laptop computer pre-loaded with software to produce a “real time” line graph of the readings from each sensor.

Successful dispersion is indicated by a rise in the starting relative humidity reading of at least an additional 15% as shown in Figure 1.  Readings of over 100% would suggest that the sensor was close to the nozzle.

VHP Quality Control

VHP Disinfection Quality Assurance

By monitoring the graph Dortek staff are able to identify instantly any area in the room that is not being subjected to the disinfectant vapour by a failure of the sensor to record the expected rise in humidity as shown in Figure 2.  At this stage the operative can run a series of equipment checks from outside the target area but if the problem can not be rectified the disinfection can be stopped and entry gained to the problem area to allow adjustment to the nozzle placement or the addition of an extra nozzle to the target area before restarting the disinfection process.

VHP Quality Control

Through experience and in VHP disinfection quality assurance, and the expertise of our operatives when siting the nozzles we usually find that the dispersion of the vapour is even throughout the target area first time.  However, our real time monitoring provides both us and our clients the assurance that the VHP has been successfully dispersed, even to the areas thought to be least accessible, allowing the client the confidence to commission areas prior to receiving biological validation results which can take up to seven days to determine.  A copy of the generated graph is provided to the customer at the end of the VHP disinfection process.

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