{"data":{"id":"us/40-cfr-98.153","jurisdiction":"us","citation":"40 CFR 98.153","heading":"Calculating GHG emissions.","body":"(a) The mass of HFC-23 generated from each HCFC-22 production process shall be estimated by using one of two methods, as applicable:\n(1) Where the mass flow of the combined stream of HFC-23 and another reaction product (e.g., HCl) is measured, multiply the weekly (or more frequent) HFC-23 concentration measurement (which may be the average of more frequent concentration measurements) by the weekly (or more frequent) mass flow of the combined stream of HFC-23 and the other product. To estimate annual HFC-23 production, sum the weekly (or more frequent) estimates of the quantities of HFC-23 produced over the year. This calculation is summarized in Equation O-1 of this section:\nWhere:\nG23 = Mass of HFC-23 generated annually (metric tons).\nc23 = Fraction HFC-23 by weight in HFC-23/other product stream.\nFp = Mass flow of HFC-23/other product stream during the period p (kg).\np = Period over which mass flows and concentrations are measured.\nn = Number of concentration and flow measurement periods for the year.\n10−3 = Conversion factor from kilograms to metric tons.\n(2) Where the mass of only a reaction product other than HFC-23 (either HCFC-22 or HCl) is measured, multiply the ratio of the weekly (or more frequent) measurement of the HFC-23 concentration and the weekly (or more frequent) measurement of the other product concentration by the weekly (or more frequent) mass produced of the other product. To estimate annual HFC-23 production, sum the weekly (or more frequent) estimates of the quantities of HFC-23 produced over the year. This calculation is summarized in Equation O-2 of this section, assuming that the other product is HCFC-22. If the other product is HCl, HCl may be substituted for HCFC-22 in Equations O-2 and O-3 of this section.\nWhere:\nG23 = Mass of HFC-23 generated annually (metric tons).\nc23 = Fraction HFC-23 by weight in HCFC-22/HFC-23 stream.\nc22 = Fraction HCFC-22 by weight in HCFC-22/HFC-23 stream.\nP22 = Mass of HCFC-22 produced over the period p (kg), calculated using Equation O-3 of this section.\np = Period over which masses and concentrations are measured.\nn = Number of concentration and mass measurement periods for the year.\n10−3 = Conversion factor from kilograms to metric tons.\n(b) The mass of HCFC-22 produced over the period p shall be estimated by using Equation O-3 of this section:\nWhere:\nP22 = Mass of HCFC-22 produced over the period p (kg).\nO22 = mass of HCFC-22 that is measured coming out of the Production process over the period p (kg).\nU22 = Mass of used HCFC-22 that is added to the production process upstream of the output measurement over the period p (kg).\nLF = Factor to account for the loss of HCFC-22 upstream of the measurement. The value for LF shall be determined pursuant to § 98.154(e).\n(c) For HCFC-22 production facilities that do not use a destruction device or that have a destruction device that is not directly connected to the HCFC-22 production equipment, HFC-23 emissions shall be estimated using Equation O-4 of this section:\nWhere:\nE23 = Mass of HFC-23 emitted annually (metric tons).\nG23 = Mass of HFC-23 generated annually (metric tons).\nS23 = Mass of HFC-23 sent off site for sale annually (metric tons).\nOD23 = Mass of HFC-23 sent off site for destruction (metric tons).\nD23 = Mass of HFC-23 destroyed on site (metric tons).\nI23 = Increase in HFC-23 inventory = HFC-23 in storage at end of year—HFC-23 in storage at beginning of year (metric tons).\n(d) For HCFC-22 production facilities that use a destruction device connected to the HCFC-22 production equipment, HFC-23 emissions shall be estimated using Equation O-5 of this section:\nWhere:\nE23 = Mass of HFC-23 emitted annually (metric tons).\nEL = Mass of HFC-23 emitted annually from equipment leaks, calculated using Equation O-6 of this section (metric tons).\nEPV = Mass of HFC-23 emitted annually from process vents, calculated using Equation O-7 of this section (metric tons).\nED = Mass of HFC-23 emitted annually from destruction device (metric tons), calculated using Equation O-8 of this section.\n(1) The mass of HFC-23 emitted annually from equipment leaks (for use in Equation O-5 of this section) shall be estimated by using Equation O-6 of this section:\nWhere:\nEL = Mass of HFC-23 emitted annually from equipment leaks (metric tons).\nc23 = Fraction HFC-23 by weight in the stream(s) in the equipment.\nFGt = The applicable leak rate specified in Table O-1 of this subpart for each source of equipment type and service t with a screening value greater than or equal to 10,000 ppmv (kg/hr/source).\nNGt = The number of sources of equipment type and service t with screening values greater than or equal to 10,000 ppmv as determined according to § 98.154(i).\nFLt = The applicable leak rate specified in Table O-1 of this subpart for each source of equipment type and service t with a screening value of less than 10,000 ppmv (kg/hr/source).\nNLt = The number of sources of equipment type and service t with screening values less than 10,000 ppmv as determined according to § 98.154(j).\np = One hour.\nn = Number of hours during the year during which equipment contained HFC-23.\nt = Equipment type and service as specified in Table O-1 of this subpart.\n10−3 = Factor converting kg to metric tons.\n(2) The mass of HFC-23 emitted annually from process vents (for use in Equation O-5 of this section) shall be estimated by using Equation O-7 of this section:\nWhere:\nEPV = Mass of HFC-23 emitted annually from process vents (metric tons).\nERT = The HFC-23 emission rate from the process vents during the period of the most recent test (kg/hr).\nPRp = The HCFC-22 production rate during the period p (kg/hr).\nPRT = The HCFC-22 production rate during the most recent test period (kg/hr).\nlp = The length of the period p (hours).\n10−3 = Factor converting kg to metric tons.\nn = The number of periods in a year.\n(3) The total mass of HFC-23 emitted from destruction devices shall be estimated by using Equation O-8 of this section:\nWhere:\nED = Mass of HFC-23 emitted annually from the destruction device (metric tons).\nFD = Mass of HFC-23 fed into the destruction device annually (metric tons).\nD23 = Mass of HFC-23 destroyed annually (metric tons).\n(4) For facilities that destroy HFC-23, the total mass of HFC-23 destroyed shall be estimated by using Equation O-9 of this section:\nWhere:\nD23. = Mass of HFC-23 destroyed annually (metric tons).\nFD = Mass of HFC-23 fed into the destruction device annually (metric tons).\nDE = Destruction Efficiency of the destruction device (fraction).","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 98—MANDATORY GREENHOUSE GAS REPORTING","Subpart O—HCFC-22 Production and HFC-23 Destruction"],"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":"afb457812e1093c4fe15bae854cd87739558fd134198099438d7c6558f08e4ac","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-98.152","next":"us/40-cfr-98.154"},"notice":"GroundRules: Original legal text. Not legal advice."}