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Montreal Protocol
(redirected from Ozone Layer Protection)

   Also found in: Wikipedia 0.02 sec.
Montreal Protocol, officially the Protocol on Substances That Deplete the Ozone Layer, treaty signed on Sept. 16, 1987, at Montreal by 25 nations; 168 nations are now parties to the accord. The protocol set limits on the production of chlorofluorocarbons chlorofluorocarbons (CFCs), organic compounds that contain carbon, chlorine, and fluorine atoms. CFCs are highly effective refrigerants that were developed in response to the pressing need to eliminate toxic and flammable substances, such as sulfur dioxide and
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 (CFCs), halons, and related substances that release chlorine or bromine to the ozone layer ozone layer or ozonosphere, region of the stratosphere containing relatively high concentrations of ozone, located at altitudes of 12–30 mi (19–48 km) above the earth's surface.
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 of the atmosphere. On the basis of increasing scientific knowledge about the effects of CFCs and halons on the ozone layer, the original protocol has been amended several times. At meetings in London (1990), Copenhagen (1992), Vienna (1995), and Montreal (1997) amendments were adopted that were designed to speed up the phasing out of ozone-depleting substances; not all parties to the main protocol are parties to these amendments. The production and consumption of halons was phased out by Jan. 1, 1994, and of CFCs, carbon tetrachloride, methyl chloroform, and hydrobromofluorocarbons by Jan. 1, 1996, subject to an exception for agreed essential users. Methyl bromide was to be phased out by 2005 but a number of users of the chemical have won temporary exceptions from the ban, and hydrochlorofluorocarbons are to be phased out by 2020. (Phaseout dates are later for developing countries.)

Under the protocol, the ozone-depleting potential, or ODP, of any substance is measured with respect to an equal mass of CCl3F, or CFC-11, which is assigned a value of 1.0. Most other CFCs have ODPs that range from about 0.5 to about 1.3. Hydrochlorofluorocarbons, which are being used as transitional replacements (until 2020) for CFCs in refrigeration, have ODPs that are generally less than 0.5. Hydrofluorocarbons, which are also replacing CFCs as refrigerants, have ODPs of zero. Ozone-depleting potentials are based on existing scientific knowledge and are to be reviewed and revised periodically.

Bibliography

See D. E. Newton, The Ozone Dilemma(1995).



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Carolina Congressman David Price (r) visited Arysta Life Sciences headquarters in Cary, NC, to congratulate the company's NA Pres Bill Lewis and staff on its EPA Ozone Layer Protection Award for its MIDAS fumigant.
An official in charge of issues concerning ozone layer protection at the Ministry of International Trade and Industry said, "We think a cutback in the production of CFCs is the utmost priority for developing countries, and we would like to discuss whether the proposed regulation on HCFCs would impair their efforts to curb CFCs.
1 Refrigerant production and consumption in Russia; Russia's adherence to the execution of international duties connected with ozone layer protection 5.
 
 
 
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