The system overcomes the problem of the Hepa (high efficiency particulate arrestance) filters used in the cleanroom industry becoming colonised by microorganisms, particularly bacteria and fungi.
Research at a number of hospitals in the US and Holland revealed extensive fungal colonisation of both the first- and second-line filters, and in several cases the filters had only been in use for a few weeks.
It is not well recognised that Hepa filters can be a source of contamination, according to Hanovia. But the large surface area of these filters, combined with a constant through-flow of nutrient-laden air, provides an ideal breeding ground for bacteria and fungi.
"Most operators assume that with proper Hepa air filtration systems in place the air supply is safe; this is clearly not the case," according to the company.
So what are the implications for manufacturers? Cleanrooms rely on positive pressure, so that every time the door is opened, air is expelled outwards rather than inwards. Microorganisms growing through the filter media can block it and cause pressure to drop, resulting in reduced efficiency and the risk of quality problems that could result in lost batches.
In addition, through-growth of fungi can also result in the release of spores on the cleanroom side of the filter, compromising the integrity of the cleanroom, while it is known that Hepa does not stop viruses, and this could be an issue for production units making biologicals, for example.
Hanovia's solution is to sterilise the air with UV light before it reaches the filter. UV disinfects all incoming and recirculated air and is effective against all known microorganisms, including bacteria, fungi and their spores, with a kill rate greater than 99.99 per cent.
The company has designed a system consisting of a UV lamp, enclosed within a protective quartz sleeve, which can irradiate the air passing through it and destroy all air-borne microbial contaminants. It can extend filter life by several months, with cost benefits, and also removes the need to use chemical disinfectants.
"Improvements, both in terms of cleanroom air quality and in staff health should also be noticeable, with less contamination and a lowered risk of infection," claims Hanovia.
For more information on Hanovia's UV systems for cleanroom applications, visit the company's website.