US lawWashingtonRegulationsTitle 173 — ECOLOGY, DEPARTMENT OFChapter 173-476 — AMBIENT AIR QUALITY STANDARDS173-476-010WAC 173-476-010WAC 173-476-010. PurposeLast amended: 2013Year: 2026Length: 22 wordsOfficial source This chapter establishes maximum acceptable levels in the ambient air for particulate matter, lead, sulfur dioxide, nitrogen oxides, ozone, and carbon monoxide.NextWAC 173-476-020