What type of refrigerant is being phased out due to environmental regulations?

The correct response highlights R-22, commonly known as Freon, as the refrigerant being phased out due to environmental regulations. R-22 is a hydrochlorofluorocarbon (HCFC) which has been identified as harmful to the ozone layer and contributes to global warming. The Environmental Protection Agency (EPA) under the Montreal Protocol has established a timeline for the gradual reduction and eventual total phase-out of R-22, motivating manufacturers to develop and transition to more environmentally friendly alternatives.

In contrast, while R-410A, R-32, and R-134A are also refrigerants used in various HVAC applications, they do not carry the same environmental concerns as R-22. R-410A and R-32 are considered more environmentally responsible options as they do not deplete the ozone layer, though they still have potential global warming impacts. R-134A, used primarily in auto air conditioning, is also being phased out but for different reasons connected to its high global warming potential compared to newer options. Thus, R-22 represents the primary refrigerant subject to an aggressive phase-out strategy due to its environmentally detrimental effects.