What distinguishes R-134a from R-12 in terms of environmental impact?

R-134a is distinguished from R-12 by its significantly lower ozone depletion potential (ODP). R-12, a chlorofluorocarbon (CFC), has been found to contribute to the depletion of the ozone layer due to the presence of chlorine atoms that are released into the atmosphere. These chlorine atoms can break down ozone molecules, leading to greater environmental harm.

In contrast, R-134a, which is a hydrofluorocarbon (HFC), does not contain chlorine and therefore has an ODP of zero. This means that R-134a does not contribute to ozone layer depletion. The transition from R-12 to R-134a was part of a broader international effort, particularly under the Montreal Protocol, aimed at phasing out substances that are harmful to the ozone layer. The lower environmental impact of R-134a in terms of ozone depletion makes it a more sustainable choice for refrigerants in automotive and other cooling applications.