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What are the breakdown products?
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Studies funded by AFEAS, the Commission of the European Communities, and the United
States Environmental Protection Agency indicate that most of the alternative fluorocarbons
can be expected to break down in the lower atmosphere to yield simple inorganic species,
including carbon oxides, hydrogen halides, formyl fluoride, and carbonyl halides.
Trifluoroacetyl halides are also likely to be formed from HCFC-123, HCFC-124, HFC-134a
and HFC-227ea.
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Will these breakdown products persist in the atmosphere?
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These breakdown products will not persist in the atmosphere. Hydrogen chloride and
fluoride are removed from the atmosphere by dissolution in cloud water and subsequent
deposition in rain, on average, in less than about two weeks.
The formyl fluoride and carbonyl and trifluoroacetyl halides are not expected to persist in the
atmosphere for longer than a few months. They will be taken up by cloud water or by ocean
and land surfaces and subsequently hydrolyzed to formic acid, carbon dioxide and
trifluoroacetic acid respectively, together with the corresponding hydrochloric and
hydrofluoric acids.
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What is the potential environmental impact of the breakdown products?
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Even if hundreds of thousands of tons of the new fluorocarbons were released each year,
studies show that they would not contribute appreciably to the current chloride or fluoride
burden of the biosphere. Any trifluoroacetic acid formed will be present at such low
concentrations in rain or sea water (parts per billion levels or less) that adverse effects are not
expected. Nevertheless, the ultimate environmental fate of this compound has been
evaluated. (See accompanying summary on Environmental Fate of Trifluoroacetyl Halides.)
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