Ill. Admin. Code tit. 35, § 203.2510 - Criteria

For this Subpart, the emissions from a new major stationary source or major modification will be considered to cause or contribute to a violation of a NAAQS if such source or modification would exceed the following significance levels at any locality that does not or would not meet the applicable NAAQS.

Pollutant	Significant Level (µg/m3)
	Annual Average	24-hour Average	8-hour Average	3-hour Average	1-hour Average
SO2	1.0	5		25
PM10	1.0	5
PM2.5	0.3	1.2
NO2	1.0
CO			500		2,000

Notes

Ill. Admin. Code tit. 35, § 203.2510

Added at 49 Ill. Reg. 6237, effective 4/23/2025