Distribution challenge in H2O2 bio-decontamination cycle

Regardless of the application, the size of the enclosure or the environment conditions, every H2O2 bio-decontamination cycle must deal with a geometrical problem.

In fact, the decontamination agent is always released into the area somewhere in the space, but it must reach every corner of the enclosure to be treated for a successful H2O2 bio-decontamination cycle.

This is a well-known challenge for those who want to perform fast cycles in complex spaces. A clarification may be useful at this point.


In any H2O2 bio-decontamination cycle there may be two different limitations linked with agent distribution:

  • diffusion limit
  • time limit


Diffusion limit

The inability to reach a specific point of the area is linked with the spread capability of the decontamination agent. Good examples may be:

  • the shadow effect behind physical objects in sprayed H2O2 decontamination method
  • a door closed that does not allow the distribution in a specific area.

In both cases, longer exposure would not help, as the agent will never get to that specific point. The problem may be solved only through different positioning of objects and space configuration.


Time limit

The decontamination agent is actually able to reach every point of the area, but it may take longer time than expected to get a certain result on a specific spot. In this case repositioning of objects may help, but the issue can be solved easily with a longer cycle time. A good example is H2O2 vapor decontamination method (V-PHP), where the gas can reach every point of the space in time, but longer time may be required in case of big areas or complex spaces.


Demonstrating a proper distribution of the sporicidal in RABS application is one of the requirements of New Annex 1.


If you would like to get support in performing a specific risk assessment to identify potential critical issues and define right cycle settings, contact us to talk with our V-PHP biodecontamination specialists.