Which refrigerant has a zero Ozone Depletion Potential (ODP), low Global Warming Potential (GWP), and is highly flammable?

The correct answer, which identifies refrigerants with a zero Ozone Depletion Potential (ODP), low Global Warming Potential (GWP), and high flammability, is hydrocarbons (HCs). Hydrocarbons, such as propane (R-290) and isobutane (R-600a), are naturally occurring compounds that do not deplete the ozone layer and generally have a very low global warming impact. This makes them environmentally friendly alternatives to traditional refrigerants.

Hydrocarbons are conducive to use in refrigeration systems due to their efficient thermodynamic properties, and while they are highly flammable, safety measures can mitigate risks in applications where they are used. This characteristic of flammability is an important consideration when selecting a refrigerant, as it necessitates careful handling and proper system design to minimize hazards.

In contrast, R-134a and R-123 both have some Ozone Depletion Potential: R-134a has an ODP of 0 but a relatively high GWP, while R-123 is not considered a low-GWP alternative. R-500, a blend that includes substances with ODP, does not align with the requirement for zero ODP, nor does it typically exhibit characteristics of low environmental