Cleanroom air quality standards include traditional non viable (dead) particle counts per ISO-14644-1 and FedStd 209E as well as viable (live) particle counts per FDA Current Good Manufacturing Practices (cGMP) under 21 CFR Parts 210/211.
Figure 1. Cleanroom particle counter
Non viable testing is done with laser particle counters. Cleanrooms use HEPA filtration to reduce particle count from lab level half a million particles per cubic foot to as low as 100 particles per cubic foot (class 100 or ISO-5). It is used for cleanrooms in all industries.
US FED STD 209E Cleanroom Standards | Cleanroom Classifications
Table 1: FED STD 209E – particles per cubic foot.
ISO 14644-1 Cleanroom Standards | Cleanroom Classifications
Table 2. ISO-14644-1 Cleanroom classifications – particles per cubic meter
Figure 2. Settled plate for cleanroom viable testing
Viable particles include bacteria, molds, and yeast. Viable testing is mandated by FDA CGMP practices under 21 CFR Parts 210/211, and EMEA GMP Annex 1 (Europe), and USP797 and 800 (pharmaceutical compouding in USA). Typically, samples are collected using settled plates with some type of media. The plates are placed in the cleanroom at specific locations for 4 hours and then are then sent off to analytical labs for incubation and measurement. Other methods of testing include air sampling onto settled plate or swabing on surfaces to look for viable contaminants.
Cleanroom air quality standards include both non viable and viable contaminants. Non viable (not alive) are measured with laser particle counters. Cleanrooms are classified by ISO-14644-1 and FEDSTD 209E based on quantity and size of non viable particles. Viable contaminants measurement is mandated by FDA Current Good Manufacturing Practices under 21 CFR Parts 210/211. Viable contaminants are typically measured via settled plates.
The author Anthony Chien has worked at American Cleanroom Systems for past 12 years. He has more than 40 years of cleanroom experience. Anthony has a BS and MS in Electrical Engineering specializing in semiconductor manufacturing from the University of Illinois. American Cleanroom Systems is a design build modular cleanroom manufacturer based in Rancho Santa Margarita CA. It is expert in ISO-5 through ISO-8 (class 100 to class 100k) modular cleanrooms for pharmaceutical cleanrooms, medical device cleanrooms, and industrial cleanrooms.
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