How many times can an expendable refrigerant be used?

Expendable refrigerants are designed for single use, which is why the correct answer is that they can only be used once. These refrigerants are typically employed in systems where they are not recycled or reclaimed, such as in certain types of self-contained refrigeration units or in specific applications like certain disposable refrigerant cans.

Once the refrigerant is released into the environment or utilized, it cannot be effectively reused or returned to a usable state due to contamination, lack of recovery measures, or system design that does not allow for retrieval. Consequently, their single-use nature reflects regulatory, environmental, and operational considerations in the HVAC industry.