Tuesday, 26 January 2016

Disinfection of active air-samplers



Avoiding cross-contamination when using microbiological air-samplers is a key activity. But how effective is the procedure? To evaluate this, Tim Sandle and Ravikrishna Satyada have written a paper based on test data. The abstract reads:

Active (volumetric) air-sampling is an important component of the environmental monitoring of cleanrooms. It is important that the results of such monitoring are accurate. One aspect of ensuring that the result is ‘valid’ is through minimising cross-contamination. The ‘at risk’ part of the sampler is the head. There are three alternatives to control cross-contamination during active air sampling contamination control: using multiple air sampler, autoclaving the sampler head in-between samples, or disinfecting the sampler head intermittently. This paper summarises a study where a disinfectant (70% isopropyl alcohol) was used to disinfect the head of an impaction air sampler between sampling sessions (spray-and-wipe technique). The study examined two factors: disinfectant decontamination effectiveness and the potential for the inhibition of microbial growth. With decontamination effectiveness, successive operations of an air sampler were examined within different cleanroom grades; with microbial growth inhibition studies, different disinfection time points were assessed. The paper concludes that this method of contamination control is effective and applicable to most cleanroom monitoring situations: it is unlikely to allow carry-over of microbial contamination and it is not shown to cause inhibition of microbial growth.

The paper is published in the European Journal of Parenteral and Pharmaceutical Science. The reference is:

Sandle, T. and Satyada, R. (2015) Assessment of the disinfection of impaction air sampler heads using 70% IPA, as part of cleanroom environmental monitoring, European Journal of Parenteral and Pharmaceutical Science, 20 (3): 94-99

For a copy, please contact Tim Sandle

Posted by Dr. Tim Sandle

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