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Ozone Depleting Chemicals


CFCs


The destruction of ozone is accelerated by certain trace gases containing
nitrogen, hydrogen, bromine, and chlorine. These are referred to as ozone
depletion chemicals.



Consumption of ozone depleting substances expressed as million tonnes of
ozone depletion potential (ODP), 1989-2009.


ODP is a number that refers to the amount of ozone depletion caused by a
chemical substance. Consumption of ozone depleting substances has largely
been reduced in the past 20 years.

Data source: GEO Data Portal, compiled from the UNEP Secretariat for the
Vienna Convention and the Montreal Protocol (UNEP 2010)

 

The most commonly
known ozone depletion chemicals (ODCs) are the CFCs or chlorofluorocarbons. Over
the last 30 years man-made CFCs have been the main cause of stratospheric ozone
depletion. 

CFCs however, are
not the only ozone-depleting chemicals. Other ODCs include the methylhalides,
carbon tetrachloride (CCl4), carbon tetrafluoride (CF4), and the halons which
contain bromine instead of chlorine. Such compounds are called halocarbons.

Carbon tetrachloride
(CCl4), despite its toxicity, was first used in the early 1900s as a fire
extinguishing agent, and more recently as an industrial solvent, an agricultural
fumigant, and in many other industrial processes including petrochemical
refining, and pesticide and pharmaceuticals production. Recently it has also
been used in the production of CFC-11 and CFC-12.

Methyl chloroform,
also known as 1,1,1 trichloroethane is a versatile, all-purpose industrial
solvent used primarily to clean metal and electronic parts. It was introduced in
the 1950s as a substitute for carbon tetrachloride.

Halons, unlike CFCs,
contain bromine, which also destroys ozone in the stratosphere. Halons are used
primarily in fire extinguishers. Halon-1301 has an ozone depleting potential 10
times that of CFC-11. Although the use of halons in developed countries has been
phased out since 1996, the atmospheric concentration of these potent, ozone
destroyers is still rising because of their long atmospheric lifetimes.

Methyl bromide,
another bromine-containing halocarbon, has been used as a pesticide since the
1960s.

Class I and
Class II Ozone Depleting Substances

 

Class I Ozone
Depleting Substances

Halocarbon
Number

Molecular

Formula
Name
CFC-11CCl3FTrichlorofluoromethane
CFC-12CCl2F2Dichlorodifluoromethane
CFC-113 C2Cl3F3Trichlorotrifluoroethane
CFC-114C2Cl2F4Dichlorotetrafluoroethane
CFC-115C2ClF5Chloropentafluoroethane
Halon 1011CH2BrClBromochloromethane
Halon 1202CBr2F2Dibromodifluoromethane
Halon 1211CF2ClBrBromochlorodifluoromethane
Halon 1301CF3BrBromotrifluoromethane
Halon 2402C2F4Br2Dibromotetrafluoroethane
CFC-13CClF3Chlorotrifluoromethane
CFC-111C2Cl5FPentachlorofluoroethane
CFC-112C2Cl4F2Tetrachlorodifluoroethane
CFC-211C3Cl7F3Heptachlorofluoropropane
CFC-212C3Cl6F2Hexachlorodifluoropropane
CFC-213C3Cl5F3Pentachlorotrifluoropropane
CFC-214C3Cl4F4
Tetrachlorotetrafluoropropane
CFC-215C3Cl3F5Trichloropentafluoropropane
CFC-216C3Cl2F6Dichlorohexafluoropropane
CFC-217C3ClF7Chloroheptafluoropropane
Carbon TetrachlorideCCl4Tetrachloromethane
Methyl Chloroform

CHCl3

Trichloroethane (1,1,1
Trichloroethane only)
Methyl Bromide

CH3Br

Bromomethane,
monobromomethane

Class II Ozone
Depleting Substances

HCFC NumberMolecular
Formula
 HCFC NumberMolecular
Formula
HCFC-21

CHFCl2

 HCFC-224

C3HF4Cl3

HCFC-22

CHF2Cl

 HCFC-225

C3HF5Cl2

HCFC-31

CH2FCl

 HCFC-225ca

CF3CF2CHCl2

HCFC-121

C2HFCl4

 HCFC-225cb

CF2ClCF2CHClF

HCFC-122

C2HF2Cl3

 HCFC-226

C3HF6Cl

HCFC-123

C2HF3Cl2

 HCFC-231

C3H2Cl5

HCFC-123b

CHCl2CF3

 HCFC-232

C3H2F2Cl4

HCFC-124

C2HF4Cl

 HCFC-233

C3H2F3Cl3

HCFC-124b

CHFClCF3

 HCFC-234

C3H2F4Cl2

HCFC-131

C2H2FCl3

 HCFC-235

C3H2F5Cl

HCFC-132

C2H2F2Cl2

 HCFC-241

C3H3FCl4

HCFC-133

C2H2F3Cl

 HCFC-242

C3H3F2Cl3

HCFC-141

C2H3FCl2

 HCFC-243

C3H3F3Cl2

HCFC-141b

CH3CFCl2

 HCFC-244

C3H3F4Cl

HCFC-142

C2H3F2Cl

 HCFC-251

C3H4FCl3

HCFC-142b

CH3CF2Cl

 HCFC-252

C3H4F2Cl2

HCFC-151

C2H4FCl

 HCFC-253

C3H4F3Cl

HCFC-221

C3HFCl6

 HCFC-261

C3H5FCl2

HCFC-222

C3HF2Cl5

 HCFC-262

C3H5F2Cl

HCFC-223

C3HF3Cl4

 HCFC-271

C3H6FCl