Cleanroom Classifications

Discover the different classes within the cleanroom ISO standards and their Federal Standard and GMP equivalent. These tables detail the air changes and particle counts that define each class. 

Read About How We Build Cleanrooms

Air Changes by Cleanroom Classification

This table details the recommended air changes per hour for ISO 14644-1:2015 cleanrooms and their associated GMP Grade and Federal Standard.

Cleanroom Standard	Cleanroom Classification Guidelines
ISO 14644-1	Class 3	Class 4	Class 5	Class 6	Class 7	Class 8
Federal Standard 209E	1	10	100	1,000	10,000	100,000
EU GMP	-	-	A/B	-	C	D
Air changes / hour	360-540	300-540	240-480	150-240	60-90	5-48

For cleanrooms and clean zones.

ISO 14644-1:2015 Cleanroom Classification

This table details the air cleanliness class by particle concentration.

ISO Classification Number	Maximum allowable concentrations (particles/m3) for particles equal to and greater than the considered sizes, shown below
	≥0.1µm	≥0.2µm	≥0.3µm	≥0.5µm	≥1µm	≥5.0µm
ISO Class 1	10b	d	d	d	d	e
ISO Class 2	100	24b	10b	d	d	e
ISO Class 3	1,000	237	102	35b	d	e
ISO Class 4	10,000	2,370	1,020	352	83b	e
ISO Class 5	100,000	23,700	10,200	3,520	832	d,e,f
ISO Class 6	1,000,000	237,000	102,000	35,200	8,320	293
ISO Class 7	c	c	c	352,000	83,200	2,930
ISO Class 8	c	c	c	3,520,000	832,000	29,300
ISO Class 9g	c	c	c	35,200,000	8,320,000	293,000

For cleanrooms and clean zones shown in ISO 14644-1:2015

Cleanroom Limits for Airborne Particulate Contamination

Clean room and clean air device classification, in relation to GMP (2008).

Cleanroom Standard		Maximum permitted number of particles /m³
EU GMP Grade	ISO EN 14644-1	At rest ≥0.5µm	At rest ≥5.0µm	In operation ≥0.5µm	In operation ≥5.0µm
A	5	3,520	20	3,520	20
B	5	3,520	29	352,000	2,900
C	7	352,000	2,900	3,520,000	29,000
D	8	3,520,000	29,000	Not defined	Not defined

For cleanrooms and clean zones