Final answer:
Using an open flame to heat a refrigerant tank can have dangerous consequences, including venting refrigerant to the atmosphere, causing the tank to explode and potentially injuring people nearby, and decomposition of the refrigerant that can lead to the formation of toxic materials.
Step-by-step explanation:
Never use an open flame to heat a refrigerant tank because it can result in a venting refrigerant to the atmosphere, the tank may explode, causing serious injury to people nearby, and the refrigerant in the tank may decompose, forming a toxic material.