Destructive Lifetime of ODS
The destructive lifetime of ODS may range between 100 and 400 years, depending on the type. Therefore, one molecule of ODS may destroy hundreds of thousands of ozone molecules during its atmospheric lifetime.
Ozone-depleting substances vary in their capacity to destroy ozone molecules. Scientists have developed a method for characterizing the relative depletion caused by different ODS. Ozone-Depleting Potential (ODP) measures the relative potency of ODS compared to a reference compound. The reference gas CFC-11 is defined to have an ODP of 1.0. This ratio enables a comparison between different chemicals. For example, one molecule of Halon 1301 (ODP = 10) is 10 times more detrimental to the stratospheric ozone layer than one molecule of CFC-11.
| ODS | ODP | ODS Description |
|---|---|---|
Halon 1301 |
10 |
Halon 1301 is an example of a halon. Halons are compounds consisting of bromine, chlorine, fluorine, and carbon. Other common halons are halon 1211 and halon 2402. |
Carbon tetrachloride |
1.10 |
Carbon tetrachloride is a compound consisting of one carbon atom and four chlorine atoms (CCl4). |
CFC-12 |
1.0 |
CFC-12 is an example of a chlorofluorocarbon (CFC). Other common CFCs are CFC-11, CFC-113, CFC-114, and CFC-115. CFCs consist of chlorine, fluorine, and carbon. |
HBFC-22B1 |
0.74 |
HBFC-22B1 is an example of a hydrobromofluorocarbon (HBFC). HBFCs are compounds consisting of hydrogen, bromine, fluorine, and carbon. |
Methyl bromide |
0.60 |
Methyl bromide is a compound consisting of carbon, hydrogen, and bromine (CH3Br). |
Chlorobromomethane |
0.12 |
Chlorobromomethane, also known as CBM or bromochloromethane, is a compound consisting of bromine, chlorine, and carbon (CH2BrCl). |
Methyl chloroform |
0.10 |
Methyl chloroform is a compound consisting of carbon, hydrogen, and chlorine (CH3CCl3). |
HCFC-142b |
0.065 |
HCFC-142b is an example of a hydrochlorofluorocarbon (HCFC). HCFCs are compounds consisting of hydrogen, chlorine, fluorine, and carbon. |
