Viable airborne microorganism

The efficacy of the filters through which the air is passed should be monitored at predetermined intervals. Air quality may be monitored by volumetric air sampler or settle plate. Table 21.2 describes the maximum concentrations of non-viable particles and viable airborne microorganisms permitted in the four grades of air. 

In active monitoring, air sampling instruments bring a specific volume of air into a collection vessel. The main methods that are used for sampling and quantification of viable airborne microorganisms are impaction on solid surface, filtration, centrifugation, cyclones, electrostatic precipitation, and the impingement in liquids (Table 4). 

Summary reports for year (specify) for viable, nonviable, and inanimate surface is provided as (provide reference attachment number) for summary report of airborne microorganism for the year (specify). 

For the manufacture of drug products, certain processes have to be performed in clean areas. Specifications for environmental airborne particulates and viable microorganisms in cleanrooms are provided in EU Directive 91/356/EEC, Annex 1 and ISO 14644-1 1999 (which replaced FS 209E in January 2002). Details for these specifications are summarized in Table 9.2. 

Standard Procedures and Records for Monitoring Airborne Particles and/or Viable Microorganisms in Specific Areas. 

For monitoring airborne particles and viable microorganisms in specific areas, standard procedures and the relevant records should be prepared. It should include ... 

This technique has several deflciencies. First, slit samplers do not separate and differentiate the size of airborne particles. Second, between the vacuum action and the rotating plate, the medium often dehydrates which can lead to poor bacterial growth and reduction in the viable count of stress-sensitive microorganisms. Third, the collected air sample is not a true representation of the air quality since about 10% of total particles are not deposited on the impaction medium. Lastly, only large particles with sufficient inertia will deviate from the streamlines and impact onto the agar surface. Small particles (<0.5 pm) miss the agar surface and are ejected back into the atmosphere. 

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