What are some of the key issues with VHP bio-decontamination organisations need to be aware of?
Effective bio-decontamination processes are critical to the smooth running of pharmaceuticals, medical device manufacturing and other healthcare sector facilities. But when planning these activities, there are a range of questions to be answered, including what agents you use to perform the process, how you validate the results, and what must be done to ensure compliance with regulations.
This can prove challenging to many organisations, especially in an environment where revised Annex 1 regulations have resulted in updated guidelines to comply with. So what should businesses be aware of when planning these processes?
Addressing the concerns surrounding decontamination
One of the most common solutions for bio-decontamination is the use of vaporised hydrogen peroxide (widely referred to as VHP, vH202 or VPHP). Its use dates back to the 1970s and offers an alternative to Steam, ethylene oxide or radiation sterilisation. However, while it has become a commonly-used solution across the many life science sectors, it is not without its challenges.
These were spelled out clearly in a 2018 blog by the Medicines and Healthcare Products Regulatory Agency (MHRA), which highlighted the potential issues of the system when used in isolators. Its author, Andrew Hopkins, who was chairperson for the revision of Annex 1 of the EU at the time, said: “Our concern is that although under ideal conditions, VHP can achieve a reduction of biological Indicator spores of up to 6 logs, the process itself is incredibly fragile.”
He explained that when used on both direct and indirect contact parts, it can be difficult to achieve VHP penetration, while at the same time, damage and wear and tear to surfaces can lead to difficulties in decontamination.
Mr Hopkins’ conclusion, therefore, was that VHP alone could not be considered a reliable solution. Naturally, this has caused a great deal of concern within the industry, with many raising questions about what they should be doing to ensure compliance when using VHP.
The misconceptions of VHP decontamination
Another potential issue is that you may see this technology referred to as VHP sterilisation, but this is not the case. In fact, the use of VHP cannot truly be described as a full sterilisation method as it lacks the ability to penetrate deeply beneath surfaces. As such it is more properly referred to as bio-decontamination.
Understanding what this technology can and cannot do is therefore critical in developing an effective solution. While, in many cases, surface bio-decontamination may be all that is required – and as such VHP offers an appropriate solution, understanding its limitations is important in scenarios where more than surface decontamination at higher sterility assurance levels (SAL) is required.
How can the use of Enzyme Indicators help?
So what is the best way in which organisations can address these challenges and ensure their VHP bio-decontamination processes are as effective as possible?
Ensuring that all surfaces have been fully decontaminated requires careful planning in order to retain compliance with Annex 1 requirements. This is particularly important when looking to decontaminate irregular materials such as gloves. These pose a particular challenge since, as well as it being difficult to ensure the agent reaches every part of the item, the permeability of the material can also create issues.
While Annex 1 therefore recommends that “gloves be appropriately extended with fingers separated to ensure contact with the agent”, given the challenges inherent in working with such items, it is imperative that the efficacy of the decontamination process is clearly validated.
Using Enzyme Indicators (EIs) in the validation process can help greatly with this. This technology offers users much more detailed information about the process. While other solutions only offer a binary pass/fail result, EIs offer much greater insight, enabling users to refine processes and take the guesswork out of bio-decontamination processes.
Another benefit of adopting EIs is the holistic approach they provide. An effective EI process starts with planning at the earliest stage to ensure it is repeatable and eliminates the possibility for variation. Indeed, the MHRA’s blog noted that in many cases, VHP, when well controlled and validated, is a useful method for the decontamination of the surrounding workspace, e.g. an isolator environment.
With the right tools, and processes in place, the use of EIs can greatly enhance the performance of VHP bio-decontamination processes, improving the speed at which results can be obtained and providing more data to ensure compliance with Annex 1 regulations – thereby ensuring that any concerns raised by the use of this agent are addressed.
