Mesenchymal Stem Cells as Therapeutics Agents: Quality and Environmental Regulatory Aspects

Table 6

Recommended limits for viable airborne particles in the environment according to FDA-cGMP, EU-GMP, and USP.

Clean area type			Maximal number of cfu in the environment
			FDA-cGMP		EU-GMP		USP
FS209E	ISO	EU-GMP	Air sample (cfu/m^3)	Settle plates (diam. 90 mm; cfu/4 h)	Air sample (cfu/m^3)	Settle plates (diam. 90 mm; cfu/4 h)	Air sample (cfu/m^3)
M3.5 (100)	5	A	1	1	<1	<1	<3
M4.5 (1,000)	6		7	3	—	—
M5.5 (10,000)	7	B	10	5	10	5	<20
M6.5 (100,000)	8	C	100	50	100	50	<100
		D	—	—	200	100	—

The additional use of settling plates is optional.
Individual settle plates may be exposed for less than 4 hours.
Samples from class 100 (ISO 5) environments should normally yield no microbiological contaminants.