HVAC - EPA Certification Practice Exam

Which of the following is a common CFC used in refrigerants?

1. R-22

2. R-500

3. R-134a

4. R-123

The correct answer is: R-500

R-500 is indeed a common refrigerant; however, when discussing chlorofluorocarbons (CFCs) explicitly, it's essential to clarify that R-22 and R-123 also fall under this category, but to different extents. R-22 is a hydrochlorofluorocarbon (HCFC) which contains chlorine but is not classified as a pure CFC. R-123 is a fully halogenated refrigerant and is classified as a hydrochlorofluorocarbon as well. CFCs, such as R-12, were commonly used before their phase-out due to their ozone-depleting potential. A more relevant refrigerant option in this question would be R-12 if listed. R-500 is a blend of refrigerants; while it includes components that might not be strictly CFCs, its classification as a refrigerant blend could cause confusion about its standing in the context of being a traditional CFC. This context is vital for understanding the evolution and regulation of refrigerants in response to environmental concerns. Hence, while R-500 is recognized as a refrigerant, being classified primarily as an HCFC, it retains relevance among discussions about refrigerants' environmental impact compared to traditional pure