Share thisSafe for personnel and equipment—but not for undesirable organisms— hydrogen peroxide vapor is more than a post-event cleaning option.
A long term concern and challenge for many research facilities over the years has been to deal with issues of environmental and surface contaminations, both prior to and during operation. The standard to which this is upheld represents the conclusion of a risk assessment focused on the potential adverse impact on research while giving consideration to the financial consequences which could result. Manual cleaning will always exist and represents the minimum of level of accountability.With such a process, while there is no question of the efficacy of the various chemicals used, the application is entirely dependent on the quality and motivation of the individual executing the task. This makes for challenging validation of the implementation—often a visual confirmation of ‘looking clean.’ Somewhat worrying when the microorganisms being targeted are invisible to the naked eye.
Within your typical household, ‘looking clean’ suffices and various chemicals provide the basis of the cleaning solution offering reduction of bacteria and viruses where they exist. Not cleaning properly may result in unpleasant living conditions. However, as the criticality of an environment increases, so does the level of cleanliness required. The industry has long realized that it sits relatively high on the risk scale as the impact of contamination may have serious downstream consequences in a research program. Within high containment facilities (BSL-3 and 4), the need for strict bio-security is escalated even further. To deal with the issue, the research industry (along with many others) realized the benefit of a non-manual method of decontamination and the use of formaldehyde as a means of elevating cleaning protocol prevailed. However, despite being cheap, formaldehyde poses a number of safety challenges which deterred many industries from regular application. As far as space decontamination potential went, this made formaldehyde a chemical used in response to a problematic contamination as opposed to a regular regimen with a view to improving standards.
More recently, despite being widely suspected for a long time, the classification of formaldehyde as a carcinogen by the World Health Organization means the U.S. is likely to follow other parts of the world in the future and issue a total ban on the use of the chemical. Such an action will necessitate the revision of many decontamination protocols in those organizations which decided against a proactive change ahead of time.
Fortunately, proven alternatives already exist. The use of hydrogen peroxide vapor is well established both in the research sector as well as many others. The technology is accepted by the FDA and has been scrutinized to a degree far beyond anything required in other industry sectors (a welcome fact considering the number of parallels which can be drawn). For nearly 20 years the technology has been used and one does not need to look far to see why. The technology is elegantly fundamental but an advanced element of control means that more than just a simple hot plate is required. Regardless of the target application, a liquid form of hydrogen peroxide solution is flash evaporated in a controlled manner and the vapor distributed. The process continues until the right conditions are achieved and the state is maintained for a predetermined period of time. The final phase catalyzes the agent into harmless bi-products of water vapor and oxygen so as to return the environment to its original, but now sterile, condition. This residue-free characteristic aided the success of the technology, along with the added benefits of ease of validation and material compatibility, over both the long and short terms.
Over the years from its conception, the technology evolved with a focus on small contained systems such as class III glove boxes and chambers to larger volumes such as rooms and suites. From there the ability to scale up to entire buildings (up to around 3,500,000 cubic feet) was straightforward. Such growth of a technology for non-perfectly sealed applications is quite astonishing considering the fact that being a decontamination process it inherently adopts, albeit incorrectly, many of the negative attributes associated with formaldehyde.
