TABLE 2.

ISO classifications for clean rooms

ISO classification	Description	Recommended gowning (gowning builds from ISO 8 to ISO 5)	Acceptable particle count (≥0.5-μm particles/m3) (ISO 14644-1)	Recommended microbial sampling frequency	Recommended active air action levels (GFIa aseptic processing, USP<1116>)	Recommended settling plate action levels (GFI aseptic processing, USP<1116>)
5	Critical area; used for aseptic manipulations during manufacturing/testing operations (e.g., sterility testing inoculation, filling, or stoppering)	Sterile sleeves; sterile gloves	3,520	During each production/testing shift	1 CFU/m3 or <1% incident rate	1 CFU/4 h or <1% incident rate
7	Immediate buffer to ISO class 5 environment, direct support area to aseptic processing (e.g., staging area for materials entering ISO 5 area)	Sterile overalls or frock (process dependent); sterile shoe/ankle covers; sterile head cover; face mask	352,000	Risk based; if immediately adjacent to ISO class 5 area, typically each operating shift; if not directly adjacent to ISO class 5 area, typically 1 or 2 times/wk depending on criticality of processes	10 CFU/m3 or <5% incident rate	5 CFU/4 h or <5% incident rate
8	Support area where less critical functions occur, such as equipment cleaning and initial gowning	Dedicated scrubs and shop shoes; gloves; bouffant (hair cover); beard cover (as required)	3,520,000	Risk based; typically 1 or 2 times/wk depending on criticality of processes	100 CFU/m3 or <10% incident rate	50 CFU/4 h or <10% incident rate

^aGFI, guidance for industry.