1,1-Dichloro-1-fluoroethane
1,1-Dichloro-1-fluoroethane is a haloalkane with the formula. It is one of the three isomers of dichlorofluoroethane. It belongs to the hydrochlorofluorocarbon family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment.
Physiochemical properties
1,1-Dichloro-1-fluoroethane can be a non-flammable, colourless liquid under room-temperature atmospheric conditions. The compound is very volatile with a boiling point of 32°C. Its critical temperature is near 204°C. Its smell has been described as "usually ethereal".Production and use
1,1-Dichloro-1-fluoroethane is mainly used as a solvent and foam blowing agent under the names R-141b and HCFC-141b. It is a class 2 ozone depleting substance undergoing a global phaseout from production and use under the Montreal Protocol since the late 1990s. It is being replaced by HFCs within some applications.Environmental effects
[Image:HCFC141b concentration.jpg|thumb|left|upright=1.3|Growth of HCFC-141b in Earth's atmosphere since year 1993.]Image:HCFC-141b mm.png|thumb|left|HCFC-141b measured by the Advanced Global Atmospheric Gases Experiment in the lower atmosphere at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion.
The concentration of HCFC-141b in the atmosphere grew to near 25 parts per trillion by year 2016. It has an ozone depletion potential of 0.12. This is low compared to the ODP=1 of trichlorofluoromethane, which also grew about ten times more abundant in the atmosphere prior to introduction of HFC-141b and subsequent adoption of the Montreal Protocol.
HFC-141b is also a minor but potent greenhouse gas. It has an estimated lifetime of about 10 years and a 100-year global warming potential ranging 725 to 2500. This compares to the GWP=1 of carbon dioxide, which had a much greater atmospheric concentration near 400 parts per million in year 2020.