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Chlorofluorocarbons (CFCs): when derived from methane and ethane these compounds have the formulae CCl m F 4−m and C 2 Cl m F 6−m, where m is nonzero. Hydro-chlorofluorocarbons (HCFCs): when derived from methane and ethane these compounds have the formula CCl m F n H 4−m−n and C 2 Cl x F y H 6−x−y, where m, n, x, and y are nonzero.
CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years, [ 9 ] sufficiently long that it will cycle out of the troposphere and into the stratosphere . In the stratosphere, CFC-113 can be broken up by ultraviolet radiation (UV, sunlight in the 190-225 nm range), generating chlorine radicals (Cl•), which ...
Chloropentafluoroethane is a chlorofluorocarbon (CFC) once used as a refrigerant and also known as R-115 and CFC-115.Its production and consumption has been banned since 1 January 1996 under the Montreal Protocol because of its high ozone depletion potential and very long lifetime when released into the environment. [3]
Fluoroalkanes are not ozone depleting, as they contain no chlorine or bromine atoms, and they are sometimes used as replacements for ozone-depleting chemicals. [19] The term fluorocarbon is used rather loosely to include any chemical containing fluorine and carbon, including chlorofluorocarbons , which are ozone depleting.
In the late 20th and early 21st century, there has been a global movement towards the phase-out of polystyrene foam as a single use plastic (SUP). Early bans of polystyrene foam intended to eliminate ozone-depleting chlorofluorocarbons (CFCs), formerly a major component.
Chlorofluorocarbons Chlorofluorocarbons were used almost universally as refrigerants and propellants due to their relatively low toxicity and high heat of vaporization. Starting in the 1980s, as their contribution to ozone depletion became known, their use was increasingly restricted, and they have now largely been replaced by HFCs.
Image credits: Photoglob Zürich "The product name Kodachrome resurfaced in the 1930s with a three-color chromogenic process, a variant that we still use today," Osterman continues.
HCFC-142b is used as a refrigerant, as a blowing agent for foam plastics production, and as feedstock to make polyvinylidene fluoride (PVDF). [5] It was introduced to replace the chlorofluorocarbons (CFCs) that were initially undergoing a phase-out per the Montreal Protocol, but HCFCs still have a significant ozone-depletion ability.