{"data":{"id":"us/40-cfr-60.3","jurisdiction":"us","citation":"40 CFR 60.3","heading":"Units and abbreviations.","body":"Used in this part are abbreviations and symbols of units of measure. These are defined as follows:\n(a) System International (SI) units of measure:\nA—ampere\ng—gram\nHz—hertz\nJ—joule\nK—degree Kelvin\nkg—kilogram\nm—meter\nm 3—cubic meter\nmg—milligram—10 −3 gram\nmm—millimeter—10 −3 meter\nMg—megagram—10 6 gram\nmol—mole\nN—newton\nng—nanogram—10 −9 gram\nnm—nanometer—10 −9 meter\nPa—pascal\ns—second\nV—volt\nW—watt\nΩ—ohm\nµg—microgram—10 −6 gram\n(b) Other units of measure:\nBtu—British thermal unit\n°C—degree Celsius (centigrade)\ncal—calorie\ncfm—cubic feet per minute\ncu ft—cubic feet\ndcf—dry cubic feet\ndcm—dry cubic meter\ndscf—dry cubic feet at standard conditions\ndscm—dry cubic meter at standard conditions\neq—equivalent\n°F—degree Fahrenheit\nft—feet\ngal—gallon\ngr—grain\ng-eq—gram equivalent\nhr—hour\nin—inch\nk—1,000\nl—liter\nlpm—liter per minute\nlb—pound\nmeq—milliequivalent\nmin—minute\nml—milliliter\nmol. wt.—molecular weight\nppb—parts per billion\nppm—parts per million\npsia—pounds per square inch absolute\npsig—pounds per square inch gage\n°R—degree Rankine\nscf—cubic feet at standard conditions\nscfh—cubic feet per hour at standard conditions\nscm—cubic meter at standard conditions\nsec—second\nsq ft—square feet\nstd—at standard conditions\n(c) Chemical nomenclature:\nCdS—cadmium sulfide\nCO—carbon monoxide\nCO2—carbon dioxide\nHCl—hydrochloric acid\nHg—mercury\nH2O—water\nH2S—hydrogen sulfide\nH2SO4—sulfuric acid\nN2—nitrogen\nNO—nitric oxide\nNO2—nitrogen dioxide\nNOX—nitrogen oxides\nO2—oxygen\nSO2—sulfur dioxide\nSO3—sulfur trioxide\nSOX—sulfur oxides\n(d) Miscellaneous:\nA.S.T.M.—American Society for Testing and Materials","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 60—STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES","Subpart A—General Provisions"],"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":"c490a878ef8b973caa27ab93cb42e0a9f5bf431c8a9470cdb5c16dbe207c078c","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-60.2","next":"us/40-cfr-60.4"},"notice":"GroundRules: Original legal text. Not legal advice."}