CFR›Title 40›Chapter I›Part 51›Subpart M›Subject Group Agency Designation ContainsSections 51.240–51.242CorpusDaily eCFRDisplayed edition2026-04-27Last updated2026-04-27 Sections 51.240 § 51.240 General plan requirements. 51.241 § 51.241 Nonattainment areas for carbon monoxide and ozone. 51.242 § 51.242 [Reserved]