Rapid gassing may not be new, but with several regulators now pushing for it to be adopted in aseptic cleanrooms, deployment is on the rise.
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has been advocating for its adoption within the NHS for some time now. But with the long-awaited Annex 1 guidelines – for the manufacture of sterile medicinal products – expected to come into force across EU countries within the next 12 months, this technology has moved up the agenda for cleanroom operators.
There’s no doubt rapid gassing will mark a significant step change for operators who are more used to alcohol spray and wipe sterilisation methods – which are currently deployed in most cleanroom environments. Rapid gassing involves the use of vaporised hydrogen peroxide (VHP), which delivers a biological kill to a 6 log reduction.
This technique offers a level of validation and repeatability that is impossible to guarantee with the traditional ‘spray and pray’ approach, which is prone to human error. Accommodating these units in cleanroom environments will require significant investment, however, and proper preparations will need to be made.
Before this technology is deployed, there are two main areas of forward planning to consider. Firstly, operators will want to guarantee the technology enables optimum production efficiency and, secondly, they will need to ensure they have the supporting equipment and infrastructure to allow this technology to be implemented.
Any cleanroom operator looking to achieve production efficiency needs to bear in mind that speed is key when introducing VHP cleaning processes.
Traditionally, these gassing methods have relied on a four-step process – conditioning, injection, dwell time and aeration. In the past, this approach was so time consuming to complete it was usually carried out overnight.
But in a world where newly diagnosed patients require chemotherapy drugs to be produced and delivered within four hours, waiting all night for an overnight VHP cycle is inconceivable.
Rapid gassing has changed this landscape. It has reimagined and accelerated the process so that sterilisation can take place in a fraction of the time. Ideally, cleanroom operators should be looking to deploy decontamination chambers that can conduct this process in less than 30 minutes.
When it comes to production efficiency, it is also worth considering the comfort of the operator. These chambers should be ergonomically designed so technicians can move equipment around easily, and potential handling errors are minimised.
The second major factor to consider is the suitability of the equipment involved and the facilities where these chambers will be housed. Rapid gassing can complete the decontamination process much faster than traditional methods, partly because the conditions in the unit are always right. But it is also because of the unit’s ability to continuously purge with VHP and flush with HEPA filtered air.
To ensure the integrity of these units, while this process takes place, seals need to be inflated repeatably throughout the course of a working day. The significance of this is that, wherever VHP decontamination units are deployed, there needs to be a ready supply of compressed air to inflate those seals.
Additional consideration also needs to be given to where the gas is being evacuated to at the end of the process. It cannot simply be pumped outside where it has the potential to drift into windows. An exhaust system should be built to allow gas to be released high up into atmosphere, where it will simply turn into oxygen and water.
Finally, operators will need to carefully consider the components going into the units. Both the packages and drugs will need to be resistant to VHP and the heat generated during the process.
If operators intend to deploy this technology within an existing cleanroom, these requirements may mean a significant refurb is necessary. So that extra investment needs to be factored in during the planning phase.
It is inevitable that rapid gassing will become a critical cleanroom technology in the not-too-distant future so operators should start considering their options now. Any new facilities being created will also need to be futureproofed to ensure their infrastructure can accommodate VHP rapid gassing – and operators are not incurring extra costs having to retrofit cleanrooms at a later date.
This article originally appeared in Cleanroom Technology August 2022 and can be viewed on page 22 here: