HCFCs

Hydrochlorofluorocarbons (HCFCs) are a class of halogenated organic compounds containing hydrogen, chlorine, fluorine, and carbon. They were developed as transitional substitutes for chlorofluorocarbons (CFCs) because they cause less depletion of the ozone layer. HCFCs still release chlorine when released to the atmosphere, so they remain ozone-depleting substances, though at lower potencies than CFCs. They also have substantial global warming potential, contributing to climate change if emitted.

HCFCs are used mainly as refrigerants for air conditioning and refrigeration equipment, and as blowing agents in polyurethane foams. They are also employed as solvents in some manufacturing processes. Common examples include HCFC-22 (chlorodifluoromethane), HCFC-141b, and HCFC-142b. Production and use have been progressively restricted under international and national rules, with phase-out schedules that vary by substance and country, and exemptions limited to essential uses in certain cases.

Environmental and health considerations include their lower ozone depletion potential relative to CFCs, but because they still release chlorine, they contribute to ozone layer depletion. Their atmospheric lifetimes range from several years to decades, and they can have high global warming potentials. Management focuses on minimizing emissions through containment, recovery, and recycling, as well as transitioning to alternatives such as hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), and natural refrigerants like carbon dioxide, ammonia, or certain hydrocarbons.

Regulatory status under the Montreal Protocol has driven substantial reductions in HCFC production and consumption, with continued controls and occasional essential-use provisions in some regions.