{"data":{"id":"us/40-cfr-table-c-5-to-subpart-c-of-part-53","jurisdiction":"us","citation":"40 CFR Table C-5 to Subpart C of Part 53","heading":"Table C-5 to Subpart C of Part 53—Summary of Comparability Field Testing Campaign Site and Seasonal Requirements for Class II and III FEMs for PM 10-2.5 and PM 2.5","body":"Candidate method Test site A B C D\nPM 2.5 Test site location area Los Angeles basin or California Central Valley Western city such as Denver, Salt Lake City, or Albuquerque Midwestern city Northeastern or mid-Atlantic city.\nTest site characteristics Relatively high PM 2.5, nitrates, and semi-volatile organic pollutants Cold weather, higher elevation, winds, and dust Substantial temperature variation, high nitrates, wintertime conditions High sulfate and high relative humidity.\nClass III Field test campaigns (Total: 5) Winter and summer Winter only Winter only Summer only.\nClass II Field test campaigns (Total: 2) Site A or B, any season Site C or D, any season.\nPM 10-2.5 Test site location area Los Angeles basin or California Central Valley Western city such as Las Vegas or Phoenix Midwestern city Large city east of the Mississippi River.\nTest site characteristics Relatively high PM 2.5, nitrates, and semi-volatile organic pollutants High PM 10-2.5 to PM 2.5 ratio, windblown dust Substantial temperature variation, high nitrates, wintertime conditions High sulfate and high relative humidity.\nClass III Field test campaigns (Total: 5) Winter and summer Winter only Winter only Summer only.\nClass II Field test campaigns (Total: 2) Site A or B, any season Site C or D, any season.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 53—AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS","Subpart C—Procedures for Determining Comparability Between Candidate Methods and Reference Methods"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"0181cb84960b753cbe979888642d516c4eed54b6f2114385089aa0bd01e2065b","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-table-c-4-to-subpart-c-of-part-53","next":"us/40-cfr-figure-c-1-to-subpart-c-of-part-53"},"notice":"GroundRules: Original legal text. Not legal advice."}