Introducing DryFog for cleanroom disinfection
Posted on 16. May, 2010 by admin in News-Technology
Sascha Rother from basan South Africa tells ManufacturingHub.co.za users in the pharmaceutical, biotech and cosmeticindustries about a unique, reliable and efficient solution for disinfecting cleanrooms:
Reliable and efficient disinfection of cleanrooms
Cleanroom disinfection is a routine procedure in industries dependent on microbiologically clean areas for production and R&D. This would include companies in the pharmaceutical, biotech, cosmetic, and other microbiology industries.
Surface disinfection is an integral part of this process, with a diverse range of techniques being used. Standard techniques used include:
- Wiping disinfection
- Fogging
- Thermal processes
- Gassing and UV light.
The techniques favoured by different
companies can be internally elected, based on effort and efficiency, or externally imposed, by regulatory bodies.
Regulatory standards for microbiological cleanliness set requirements for regular, certified bio-decontamination of specific areas. A company may have one or several areas that require regular disinfection in order to provide a microbiologically clean environment.
The use of a dry fog system based on hydrogen peroxide and peracetic acid offers a reliable, highly effective (6 logreduction) and environmental friendly solution.
What is Dry Fog?
As its name indicates, Dry Fog is a biocide aerosol which is released into the air’ Small super-lightweight dry fog particlesdistribute evenly across a large area.
Dry fog is defined as an aerosol particle which is less then 10µm big. It is also referred to as ‘Ultra Fine Atomization’.
The dry fog system generates aerosols of the size of 7.5µm. Due to the light-weight drifting nature of the particle, top, side and bottom surfaces will be covered.
What is the advantage?
Comprehensive bio-decontamination: Dry fog disperses better then wet fog. This leads to considerably more surface contact and even difficult to reach surfaces will be decontaminated.
Portability: The Dry Fog is easy to assemble
Safety: As a ‘dry’ material, there is less chance of reaction to electronic components that with traditional wet-fog products. There is no need to cover or to remove electronic components.
Durability: The aerosol particles do not collapse and bind when coming into contact with other particles or the target surface. As a result there is little or no condensation, resulting in a larger surface area being evenly covered.
The Minncare Dry Fog system
The Minncare dry fog system consists of a dry fog machine and a biocide. The biocide is a stable mixture of hydrogen peroxide and peracetic acid, to which water is added. The dry fog machine relies on 5 bar (or higher) compressed and clean air or a nitrogen connection.
After fogging a cleanroom, the residuals that can remain are oxygen and acetic acid.
Procedure
With all four nozzles operating it is possible to disinfect up to 1000 m³ from one point. Several inter-connecting rooms can even be decontaminated from just one position. The biocide will be diluted with either de-ionised water or water for injection. The dilution factor depends on the relative humidity and room temperature.
The HVAC needs to be off during the fogging phase otherwise the fog can’t disperse evenly.
The optimal relative humidity should be prior to fogging less then 60% and during the fogging phase it shouldn’t exceed 80 –85%. Best sporicidal activity is between 70% – 80%. The dry fog systems allows to disinfectant rooms from 20m³ to 1,000m³.
The mini Dry Fog is for smaller environments useful like laminar flows, biohazard cabinets from 1m³ to 20m³.
In the example was a 6log reduction in spore B. Stearothermophylus ATCC 7953 achieved.
What about residuals?
In a worst case scenario the maximum of acetic acid would be <0,00002ml per m².
Whilst some pharmaceutical companies still use formaldehyde which is very toxic and highly corrosive compared to Minncare, which is biodegradable.
Budget and Environmentally friendly
Compared to normal surface disinfection, DryFog has a huge cost saving potential. For 1 m³ of room only 1,5 ml of concentrate
is required. If one combines it with reduced downtime and high efficiency it offers a reliable solution.