◆ In 2001, the 3M Company from the United States launched a new clean fire extinguishing agent named NOVEC as a new substitute of halon, which has outstanding advantages in environmental protection, toxicity characteristics and fire extinguishing performance. The chemical composition of the fire extinguishing agent is CF3CF2C(O)CF(CF3)2, which features a high boiling point, a low vapor pressure, and can be stored in a liquid state at room temperature. The agent is clear, transparent, and non-corrosive, and has a fairly sound electrical insulation performance. The chemical composition is a kind of fluorinated ketones, which is neither hydrogen fluoride (HFC) nor inert gas.