Table 3.3.

Penetration of HEPA filter media 1 made in China and common HEPA filter media made in the USA

Filtration velocity/(cm/s)	Chinese filter media l		UK filter media
	Particle size/μm		Particle size/μm
	0.1	0.3	0.1	0.3
1.25	3.25 × 10−7	2.02 × 10−6	3.30 × 10−6	3.20 × 10−6
2.50	3.64 × 10−6	1.00 × 10−5	5.40 × 10−5	2.50 × 10−5
3.50	1.53 × 10−5	2.26 × 10−5	1.20 × 10−4	3.80 × 10−5
7.00	1.41 × 10−4	5.30 × 10−3	8.50 × 10−4	1.50 × 10−4