This page provides information on compounds recognized as ozone-depleting substances () under the Montreal Protocol.
The ODS are split into two groups under the Clean Air Act: Class I ODS, such as (CFCs), and Class II ODS, such as (HCFCs).
For each ODS, this page provides the compound’s atmospheric lifetime, (ODP), (GWP), and Chemistry Abstract Service (CAS) registry numbers.
Information on acceptable ODS alternatives (e.g., hydrofluorocarbons) is available through EPA’s Significant New Alternatives Policy (SNAP) Program.
Class I ODS
Class I ODS are divided into eight groups.
Class I ODS listed in Groups 1 through 5 are identified in Title VI of the Clean Air Act.
Class I ODS listed in Groups 6 and 7, methyl bromide and hydrobromofluorocarbons, are identified in EPA's Accelerated Phaseout final rule.
Class I ODS listed in Group 8, chlorobromomethane, is identified in EPA's Chlorobromomethane Phaseout final rule.
| Chemical Name | Lifetime, in years | ODP1 (Montreal Protocol) | ODP2 (WMO 2011) | GWP1 (AR4) | GWP2 (AR5) | CAS Number |
|---|
| Group I |
| CFC-11 (CCl3F) Trichlorofluoromethane | 45 | 1 | 1 | 4750 | 4660 | 75-69-4 |
| CFC-12 (CCl2F2) Dichlorodifluoromethane | 100 | 1 | 0.82 | 10900 | 10200 | 75-71-8 |
| CFC-113 (C2F3Cl3) 1,1,2-Trichlorotrifluoroethane | 85 | 0.8 | 0.85 | 6130 | 5820 | 76-13-1 |
| CFC-114 (C2F4Cl2) Dichlorotetrafluoroethane | 190 | 1 | 0.58 | 10000 | 8590 | 76-14-2 |
| CFC-115 (C2F5Cl) Monochloropentafluoroethane | 1020 | 0.6 | 0.5 | 7370 | 7670 | 76-15-3 |
| Group II |
| Halon 1211 (CF2ClBr) Bromochlorodifluoromethane | 16 | 3 | 7.9 | 1890 | 1750 | 353-59-3 |
| Halon 1301 (CF3Br) Bromotrifluoromethane | 65 | 10 | 15.9 | 7140 | 6290 | 75-63-8 |
| Halon 2402 (C2F4Br2) Dibromotetrafluoroethane | 20 | 6 | 13.0 | 1640 | 1470 | 124-73-2 |
| Group III |
| CFC-13 (CF3Cl) Chlorotrifluoromethane | 640 | 1 | 1 | 14420 | 13900 | 75-72-9 |
| CFC-111 (C2FCl5) Pentachlorofluoroethane |
| 1 | 1 |
|
| 354-56-3 |
| CFC-112 (C2F2Cl4) Tetrachlorodifluoroethane |
| 1 | 1 |
|
| 76-12-0 |
| CFC-211 (C3FCl7) Heptachlorofluoropropane |
| 1 | 1 |
|
| 422-78-6 |
| CFC-212 (C3F2Cl6) Hexachlorodifluoropropane |
| 1 | 1 |
|
| 3182-26-1 |
| CFC-213 (C3F3Cl5) Pentachlorotrifluoropropane |
| 1 | 1 |
|
| 2354-06-5 |
| CFC-214 (C3F4Cl4) Tetrachlorotetrafluoropropane |
| 1 | 1 |
|
| 29255-31-0 |
| CFC-215 (C3F5Cl3) Trichloropentafluoropropane |
| 1 | 1 |
|
| 4259-43-2 |
| CFC-216 (C3F6Cl2) Dichlorohexafluoropropane |
| 1 | 1 |
|
| 661-97-2 |
| CFC-217 (C3F7Cl) Chloroheptafluoropropane |
| 1 | 1 |
|
| 422-86-6 |
| Group IV |
| CCl4 Carbon tetrachloride | 26 | 1.1 | 0.82 | 1400 | 1730 | 56-23-5 |
| Group V |
| Methyl Chloroform (C2H3Cl3) 1,1,1-trichloroethane | 5 | 0.1 | 0.16 | 146 | 160 | 71-55-6 |
| Group VI |
| Methyl Bromide (CH3Br) | 0.8 | 0.7 | 0.66 | 5 | 2 | 74-83-9 |
| Group VII |
| CHFBr2 |
| 1 | 1 |
|
|
|
| HBFC-12B1(CHF2Br) |
| 0.74 |
|
|
|
|
| CH2FBr |
| 0.73 | 0.73 |
|
|
|
| C2HFBr4 |
| 0.3-0.8 | 0.3-0.8 |
|
|
|
| C2HF2Br3 |
| 0.5-1.8 | 0.5-1.8 |
|
|
|
| C2HF3Br2 |
| 0.4–1.6 | 0.4–1.6 |
|
|
|
| C2HF4Br |
| 0.7–1.2 | 0.7–1.2 |
|
|
|
| C2H2FBr3 |
| 0.1–1.1 | 0.1–1.1 |
|
|
|
| C2H2F2Br2 |
| 0.2–1.5 | 0.2–1.5 |
|
|
|
| C2H2F3Br |
| 0.7–1.6 | 0.7–1.6 |
|
|
|
| C2H3FBr2 |
| 0.1–1.7 | 0.1–1.7 |
|
|
|
| C2H3F2Br |
| 0.2–1.1 | 0.2–1.1 |
|
|
|
| C2H4FBr |
| 0.07–0.1 | 0.07–0.1 |
|
|
|
| C3HFBr6 |
| 0.3–1.5 | 0.3–1.5 |
|
|
|
| C3HF2Br5 |
| 0.2–1.9 | 0.2–1.9 |
|
|
|
| C3HF3Br4 |
| 0.3–1.8 | 0.3–1.8 |
|
|
|
| C3HF4Br3 |
| 0.5–2.2 | 0.5–2.2 |
|
|
|
| C3HF5Br2 |
| 0.9–2.0 | 0.9–2.0 |
|
|
|
| C3HF6Br |
| 0.7–3.3 | 0.7–3.3 |
|
|
|
| C3H2FBr5 |
| 0.1–1.9 |
|
|
|
|
| C3H2F2Br4 |
| 0.2–2.1 | 0.2–2.1 |
|
|
|
| C3H2F3Br3 |
| 0.2–5.6 | 0.2–5.6 |
|
|
|
| C3H2F4Br2 |
| 0.3–7.5 | 0.3–7.5 |
|
|
|
| C3H2F5Br |
| 0.9–1.4 | 0.9–1.4 |
|
|
|
| C3H3FBr4 |
| 0.08–1.9 | 0.08–1.9 |
|
|
|
| C3H3F2Br3 |
| 0.1–3.1 | 0.1–3.1 |
|
|
|
| C3H3F3Br2 |
| 0.1–2.5 | 0.1–2.5 |
|
|
|
| C3H3F4Br |
| 0.3–4.4 | 0.3–4.4 |
|
|
|
| C3H4FBr3 |
| 0.03–0.3 | 0.03–0.3 |
|
|
|
| C3H4F2Br2 |
| 0.1–1.0 | 0.1–1.0 |
|
|
|
| C3H4F3Br |
| 0.07–0.8 | 0.07–0.8 |
|
|
|
| C3H5FBr2 |
| 0.04–0.4 | 0.04–0.4 |
|
|
|
| C3H5F2Br |
| 0.07–0.8 | 0.07–0.8 |
|
|
|
| C3H6FBr |
| 0.02–0.7 | 0.02–0.7 |
|
|
|
| Group VIII |
| CH2BrCl Chlorobromomethane | 0.37 | 0.12 | 0.12 |
|
|
|
Why are there multiple values given for the ODPs and GWPs?
The numbers in the “ODP1” column are from the Montreal Protocol. Some numbers have been updated as per amendments to the Protocol.
Data in the “ODP2” column come from WMO’s Scientific Assessment of Ozone Depletion: 2010.1 ODP values listed are semi-empirical and can be found in Table 5-1 of the document.
The numbers in the “GWP1” column represent global warming potentials over a 100-year time horizon. The numbers are from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report: Climate Change 2007 (AR4).2 The values listed are for direct radiative forcing and can be found in Table 2.14 of the “Physical Science Basis” contribution to the report.
The numbers in the “GWP2” column also represent global warming potentials over a 100-year time horizon. The numbers are from the IPCC Fifth Assessment Report: Climate Change 2014 (AR5). The values listed are for direct radiative forcing and can be found in Table 8.A.1 of the “Physical Science Basis” contribution to the report.3
References
WMO (World Meteorological Organization), 2011: Scientific Assessment of Ozone Depletion: 2010. Global Ozone Research and Monitoring Project—Report No. 52, Geneva, Switzerland, 516 pp.
IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp.
IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.
Class II ODS
| Chemical Name | Lifetime, in years | ODP1 (Montreal Protocol) | ODP2 (WMO 2011) | GWP1 (AR4) | GWP2 (AR5) | CAS Number |
|---|
| HCFC-21 (CHFCl2) Dichlorofluoromethane | 1.7 | 0.04 |
| 151 | 148 | 75-43-4 |
| HCFC-22 (CHF2Cl) Monochlorodifluoromethane | 11.9 | 0.055 | 0.04 | 1810 | 1760 | 75-45-6 |
| HCFC-31 (CH2FCl) Monochlorofluoromethane |
| 0.02 |
|
|
| 593-70-4 |
| HCFC-121 (C2HFCl4) Tetrachlorofluoroethane |
| 0.01-0.04 |
|
|
| 354-14-3 |
| HCFC-122 (C2HF2Cl3) Trichlorodifluoroethane |
| 0.02-0.08 |
|
| 59 | 354-21-2 |
| HCFC-123 (C2HF3Cl2) Dichlorotrifluoroethane | 1.3 | 0.02 | 0.01 | 77 | 79 | 306-83-2 |
| HCFC-124 (C2HF4Cl) Monochlorotetrafluoroethane | 5.9 | 0.022 |
|
|
| 2837-89-0 |
| HCFC-131 (C2H2FCl3) Trichlorofluoroethane |
| 0.007–0.05 |
|
|
| 359-28-4 |
| HCFC-132b (C2H2F2Cl2) Dichlorodifluoroethane |
| 0.008–0.05 |
|
|
| 1649-08-7 |
| HCFC-133a (C2H2F3Cl) Monochlorotrifluoroethane |
| 0.02–0.06 |
|
|
| 75-88-7 |
| HCFC-141b (C2H3FCl2) Dichlorofluoroethane | 9.2 | 0.11 | 0.12 | 725 | 782 | 1717-00-6 |
| HCFC-142b (C2H3F2Cl) Monochlorodifluoroethane | 17.2 | 0.065 | 0.06 | 2310 | 1980 | 75-68-3 |
| HCFC-221 (C3HFCl6) Hexachlorofluoropropane |
| 0.015–0.07 |
|
|
| 422-26-4 |
| HCFC-222 (C3HF2Cl5) Pentachlorodifluoropropane |
| 0.01–0.09 |
|
|
| 422-49-1 |
| HCFC-223 (C3HF3Cl4) Tetrachlorotrifluoropropane |
| 0.01–0.08 |
|
|
| 422-52-6 |
| HCFC-224 (C3HF4Cl3) Trichlorotetrafluoropropane |
| 0.01–0.09 |
|
|
| 422-54-8 |
| HCFC-225ca (C3HF5Cl2) Dichloropentafluoropropane | 1.9 | 0.025 | 0.02 | 122 | 127 | 422-56-0 |
| HCFC-225cb (C3HF5Cl2) Dichloropentafluoropropane | 5.9 | 0.033 | 0.03 | 595 | 525 | 507-55-1 |
| HCFC-226 (C3HF6Cl) Monochlorohexafluoropropane |
| 0.02–0.1 |
|
|
| 431-87-8 |
| HCFC-231 (C3H2FCl5) Pentachlorofluoropropane |
| 0.05–0.09 |
|
|
| 421-94-3 |
| HCFC-232 (C3H2F2Cl4) Tetrachlorodifluoropropane |
| 0.008–0.1 |
|
|
| 460-89-9 |
| HCFC-233 (C3H2F3Cl3) Trichlorotrifluoropropane |
| 0.007–0.23 |
|
|
| 7125-84-0 |
| HCFC-234 (C3H2F4Cl2) Dichlorotetrafluoropropane |
| 0.01–0.28 |
|
|
| 425-94-5 |
| HCFC-235 (C3H2F5Cl) Monochloropentafluoropropane |
| 0.03–0.52 |
|
|
| 460-92-4 |
| HCFC-241 (C3H3FCl4) Tetrachlorofluoropropane |
| 0.004–0.09 |
|
|
| 666-27-3 |
| HCFC-242 (C3H3F2Cl3) Trichlorodifluoropropane |
| 0.005–0.13 |
|
|
| 460-63-9 |
| HCFC-243 (C3H3F3Cl2) Dichlorotrifluoropropane |
| 0.007–0.12 |
|
|
| 460-69-5 |
| HCFC-244 (C3H3F4Cl) Monochlorotetrafluoropropane |
| 0.009–0.14 |
|
|
|
|
| HCFC-251 (C3H4FCl3) Monochlorotetrafluoropropane |
| 0.001–0.01 |
|
|
| 421-41-0 |
| HCFC-252 (C3H4F2Cl2) Dichlorodifluoropropane |
| 0.005–0.04 |
|
|
| 819-00-1 |
| HCFC-253 (C3H4F3Cl) Monochlorotrifluoropropane |
| 0.003–0.03 |
|
|
| 460-35-5 |
| HCFC-261 (C3H5FCl2) Dichlorofluoropropane |
| 0.002–0.02 |
|
|
| 420-97-3 |
| HCFC-262 (C3H5F2Cl) Monochlorodifluoropropane |
| 0.002–0.02 |
|
|
| 421-02-03 |
| HCFC-271 (C3H6FCl) Monochlorofluoropropane |
| 0.001–0.03 |
|
|
| 430-55-7 |
Why are there multiple values given for the ODPs and GWPs?
The numbers in the “ODP1” column are from the Montreal Protocol. Some numbers have been updated as per amendments to the Protocol.
Data in the “ODP2” column come from WMO’s Scientific Assessment of Ozone Depletion: 2010.1 ODP values listed are semi-empirical and can be found in Table 5-1 of the document.
The numbers in the “GWP1” column represent global warming potentials over a 100-year time horizon. The numbers are from the IPCC Fourth Assessment Report: Climate Change 2007 (AR4).2 The values listed are for direct radiative forcing and can be found in Table 2.14 of the “Physical Science Basis” contribution to the report.
The numbers in the “GWP2” column also represent global warming potentials over a 100-year time horizon. The numbers are from the IPCC Fifth Assessment Report: Climate Change 2014 (AR5). The values listed are for direct radiative forcing and can be found in Table 8.A.1 of the “Physical Science Basis: contribution to the report.3
References
WMO (World Meteorological Organization), 2011: Scientific Assessment of Ozone Depletion: 2010. Global Ozone Research and Monitoring Project—Report No. 52, Geneva, Switzerland, 516 pp.
IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp.
IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.