Recovered refrigerants may be reused if used back into the system it was _____ from.

Recovered refrigerants can indeed be reused in the system they were taken from, as long as they are considered safe and suitable for that specific application. The term "recovered" specifically refers to refrigerants that have been collected from a system during a maintenance procedure or a repair without being processed or recycled.

The reason "recovered" is the correct term here is that it encompasses the process of safely capturing the refrigerant from the equipment it was originally in, implying it has been removed from service for purposes such as repairs or servicing. This indicates a level of precaution and adherence to safety and environmental regulations.

In contrast, terms like "drained" and "extracted" imply a different context that might not necessarily indicate the refrigerant's condition or safety for reuse. "Cleaned" suggests a process that involves purification or treatment, which is not typically necessary for simple reuse; rather, "recovered" implies that the refrigerant can be placed back into its original system if no other issues affect its integrity or performance. Thus, utilizing recovered refrigerants returns them to their originating system in a manner that aligns with proper codes and environmentally friendly practices.