The confusion around liquefied hydrocarbons

This is a quite crucial question. With a boiling point of -15°C and an explosion limit of 7%, its physical properties indeed match those of liquefied hydrocarbons (it is gaseous at normal temperature and pressure, and can be stored in liquid form under increased pressure or reduced temperature). However, its halogen content and low calorific value indicate that it is likely not a typical alkane or alkene-based liquefied hydrocarbon, but rather an organic halide. Personal suggestions can be considered from the following perspectives: Refer to standard definitions – China’s \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB 50160) provides a clear definition of \"liquefied hydrocarbons\", which generally refer to hydrocarbons that are in gaseous state at 15°C and 0.1 MPa, and turn into a liquid state when subjected to pressure or cooling. This material contains halogens, and strictly speaking it may not be considered a \"hydrocarbon.\" It is recommended to refer to the classification criteria in the standards for categories such as \"flammable gases,\" \"liquefied hydrocarbons,\" and \"Class A/B liquids,\" rather than relying solely on the boiling point. Safety distance and tank selection: If it is decided to treat the material as a liquefied hydrocarbon, the tanks, safety distances, leak detection systems, and fire-fighting facilities must all meet the specifications required for liquefied hydrocarbons. However, halogenated substances may corrode the equipment, so additional consideration must be given to the materials and pressure relief systems. It is recommended to consult a professional agency for verification: the properties of such materials are quite special, and safety considerations cannot be handled carelessly. It is best for the design institute or safety assessment agency to provide clear recommendations for classification, based on data such as material composition, saturation vapor pressure curves, and critical temperature. If the calorific value is indeed low, other classification criteria may also apply. In short, one cannot rely solely on boiling point and lower explosion limit; component composition and combustion properties also need to be considered. As a precaution, it is recommended to consult professionals in chemical safety or look into actual cases involving similar materials.