US lawIllinoisRegulationsTitle 35 — ENVIRONMENTAL PROTECTIONCHAPTER I: POLLUTION CONTROL BOARDSUBCHAPTER c: EMISSION STANDARDS AND LIMITATIONS FOR STATIONARY SOURCESPart 212 — VISIBLE AND PARTICULATE MATTER EMISSIONSSubpart B212.12135 Ill. Adm. Code 212.121Opacity Standards (Repealed)Last amended: 1996Year: 2026Length: 7 wordsOfficial source Section 212 Section 212.121 Opacity Standards (Repealed)Next35 Ill. Adm. Code 212.122