Table 1: ISO-4644-1 cleanroom classifications
US Food and Drug Administration (FDA)
The US FDA, and associated federal bodies, publish the Code of Federal Regulations (CFR). 21 CFR Part 211 specifies the requirements for producing drug products and alongside the Guidance for Industry: Sterile Drug Products Produced by Aseptic Processing document they lay out the cleanroom classification requirements that need to be met when manufacturing drug products. In their guidance they make some modifications:
i) Focus on ISO designations 5-8.
ii) Assign equivalent Clean Area Classifications (particles/ft3)
iii) Focus on 0.5µm particle sizes
iv) Include microbiological air specifications
See Table 2 and 3 for further information.
European Union (EU)
The EU and its related governing bodies publish their own directives which lay out the requirements for classification of cleanrooms. Similar to the FDA they incorporate and expand on ISO-14644-1. EudraLex Volume 4 Annex 1: Manufacture of Sterile Medicinal Products outlines the classification requirements for cleanrooms producing medicinal products. In this guidance they categorize areas as follows:
i) Areas are classified as Grade A, B, C, or D
ii) Specify particle requirements for 0.5 µm and 5.0 µm particle sizes
iii) Provide specification for “at rest” and “in operation” states.
iv) Provide microbiological limits for specified grades
See Table 2 and 3 for further information.
Other Governing Bodies
The FDA and EU are two of the main governing bodies however many countries will have their own, and there are also other international bodies which provide regulatory guidelines on the classification of cleanrooms. These other bodies generally follow the lead of either the FDA or EU, or just wholly incorporate ISO-14644-1.