Final answer:
The 'very high-pressure refrigerant' according to the EPA's refrigerant recycling regulations is R-13. Other refrigerants like HCFC-22, HCFC-123, and HFC-134a are lower-pressure refrigerants and do not fall under this category.
Step-by-step explanation:
The refrigerant identified as a 'very high-pressure refrigerant' under the EPA's refrigerant recycling regulations is R-13. The terms used in the references provided, such as hydrochlorofluorocarbon-22 (HCFC-22), hydrochlorofluorocarbon-123 (HCFC-123), and hydrofluorocarbon-134a (HFC-134a), are all various refrigerants with different pressure levels and environmental impacts. HCFC-22, commonly referred to as R-22, is a lower-pressure refrigerant. HCFCs and HFCs like HCFC-124, HCFC-141b, and HFC-134a are designed to replace more environmentally harmful refrigerants such as CFCs (chlorofluorocarbons), but they do not fall under the category of 'very high-pressure'.
Freon-12, mentioned as a refrigerant with a boiling point of -29.8 °C, is also not classified as a very high-pressure refrigerant. Overall, the refrigerant known as R-13, or chlorotrifluoromethane, is the one that falls into the 'very high-pressure' category as per Environmental Protection Agency (EPA) standards, although it wasn't listed among the examples given.