CFR›Title 40›Chapter I›Part 60›Subpart NN ContainsSections 60.400–60.404CorpusDaily eCFRDisplayed edition2026-05-14Last updated2026-05-14 Subpart NN—Standards of Performance for Phosphate Rock Plants Sections 60.400 § 60.400 Applicability and designation of affected facility. 60.401 § 60.401 Definitions. 60.402 § 60.402 Standard for particulate matter. 60.403 § 60.403 Monitoring of emissions and operations. 60.404 § 60.404 Test methods and procedures. Source47 FR 16589, Apr. 16, 1982, unless otherwise noted. Previous Na Subpart Na—Standards of Performance for Secondary Emissions from Basic Oxygen Process Steelmaking Facilities for Which Construction is Commenced After January 20, 1983 Next NNN Subpart NNN—Standards of Performance for Volatile Organic Compound (VOC) Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Distillation Operations After December 30, 1983, and on or Before April 25, 2023