{"data":{"id":"us/40-cfr-table-c-1-to-subpart-c-of-part-53","jurisdiction":"us","citation":"40 CFR Table C-1 to Subpart C of Part 53","heading":"Table C-1 to Subpart C of Part 53—Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications","body":"Pollutant Concentration range, parts per million (ppm) Simultaneous measurements required Maximum discrepancy specification, parts per million\n1-hour 24-hour\nFirst set Second set First set Second set\nOzone Low 0.06 to 0.10 5 6 0.02\nMed. 0.15 to 0.25 5 6 0.03\nHigh 0.35 to 0.46 4 6 0.04\nTotal 14 18\nCarbon monoxide Low 7 to 11 5 6 1.5\nMed. 20 to 30 5 6 2.0\nHigh 25 to 45 4 6 3.0\nTotal 14 18\nSulfur dioxide Low 0.02 to 0.05 5 6 3 3 0.02\nMed. 0.10 to 0.15 5 6 2 3 0.03\nHigh 0.30 to 0.50 4 6 2 2 0.04\nTotal 14 18 7 8\nNitrogen dioxide Low 0.02 to 0.08 3 3 0.02\nMed. 0.10 to 0.20 2 2 0.02\nHigh 0.25 2 2 0.03\nTotal 7 8","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":"241d711175c247b7c54ac11dcdf2d862fe55a8caf2c1fbf0cd7c1050064a166c","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-53.35","next":"us/40-cfr-table-c-2-to-subpart-c-of-part-53"},"notice":"GroundRules: Original legal text. Not legal advice."}