What substances are ozone depleting?
Ozone depleting substances
- chlorofluorocarbons (CFCs)
- halons.
- carbon tetrachloride (CCl4)
- methyl chloroform (CH3CCl3)
- hydrobromofluorocarbons (HBFCs)
- hydrochlorofluorocarbons (HCFCs)
- methyl bromide (CH3Br)
- bromochloromethane (CH2BrCl)
What are Class I Ozone Depleting substances?
CFCs
In the United States, “Class I” ozone-depleting substances ( ODS. ODS include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform.
What treaty regulates ozone depleting substances?
The Montreal Protocol on Substances that
The Montreal Protocol on Substances that Deplete the Ozone Layer (the Montreal Protocol) is an international agreement made in 1987. It was designed to stop the production and import of ozone depleting substances and reduce their concentration in the atmosphere to help protect the earth’s ozone layer.
Are there regulations on production of ozone depleting gases?
Yes, the production of ozone-depleting gases is regulated under a 1987 international agreement known as the “Montreal Protocol on Substances that Deplete the Ozone Layer” and its subsequent Amendments and Adjustments.
What is causing the ozone to deplete?
Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere (see details below). CFCs and halons cause chemical reactions that break down ozone molecules, reducing ozone’s ultraviolet radiation-absorbing capacity.
What chemical elements are most commonly found in ozone depleting substances?
Ozone-depleting substances ( ODS ) generally contain chlorine, fluorine, bromine, carbon, and hydrogen in varying proportions and are often described by the general term halocarbons.
Is halon an ozone depleting substance?
Halons, which were widely used in fire extinguishers and explosion suppression systems, have an extremely high potential for ozone depletion – they are ten times more potent than chlorofluorocarbons (CFCs) – and they also act as a global warming agent – three and a half thousand times as potent as carbon dioxide (CO2).
How do CFCs destroy ozone?
Once in the atmosphere, CFCs drift slowly upward to the stratosphere, where they are broken up by ultraviolet radiation, releasing chlorine atoms, which are able to destroy ozone molecules. When sunlight returns in the spring, the chlorine begins to destroy ozone.
Is the Montreal Protocol still in effect?
The U.S. Senate unanimously approved U.S. ratification of the Montreal Protocol in 1988, and the treaty has continued to receive bipartisan support over the past thirty years.
What is the Copenhagen Amendment?
The Copenhagen Amendment provided for phase-out of consumption and production of CFCs (including fully halogenated CFCs), methyl chloroform, and carbon tetrachloride by January 1, 1996, and of halons by January 1, 1994. The amendment entered into force in 1994 and has now been ratified by 141 countries.
Is the Montreal Protocol working?
The Montreal Protocol has been successful in reducing ozone-depleting substances and reactive chlorine and bromine in the stratosphere. It is expected that the ozone layer will return to pre-1980s levels by the middle of the century and the Antarctic ozone hole by around 2060s.
