Table 2.18.

Ambient Air Quality Standards in China and America

Nationality	Standard development department	Particle concentration (μg/m3)						Allowable time with concentration larger than the limit	Remark
			Annual average	Daily average	1 h average	Limit	Average time
America	National standard for air quality in 1971	Class I		0.260				99.7 % in 1 year
		Class II		0.150				99.7 % in 1 year
		Country		0.13				95 % in 1 year
		Residential district		0.15				95 % in 1 year
		Industrial area		0.2				95% in 1 year
	In 1987 (PM10)	Class I	0.050	0.150
	In 1997 (PM2.5)		0.015	0.065				Three consecutive years with concentration not less than 98 % of the average daily concentration
China	National standard “Ambient Air Quality Standard” (GB3095-82) issued in 1982 and the revised edition in 1994	Total suspended particles
		Level 1	0.10	0.15
				(0.15)		(0.30)	(Any time)		Value in () is from the standard in 1982
		Level 2	0.20	0.30
				(0.30)		(1.00)	(Any time)		Value in () is from the standard in 1982
		Level 3	0.30	0.50
				(0.50)		(1.50)	(Any time)		Value in () is from the standard in 1982
		Inhalable particles
		Level 1	0.04	0.05
				(0.05)		(0.15)	(Any time)		Value in () is from the standard in 1982
		Level 2	0.10	0.15
				(0.15)		(0.50)	(Any time)		Value in () is from the standard in 1982
		Level 3	0.15	0.25
				(0.25)		(0.70)	(Any time)		Value in () is from the standard in 1982
	Revised standard “Ambient Air Quality Standard” in 2012 (implemented in Jan. of 2016)	PM10							In the standard, the unit has been changed from mg/m3 into μg/m3
		Level 1	0.04	0.05
		Level 2	0.07	0.15
		PM2.5
		Level 1	0.015	0.035
		Level 2	0.035	0.075