Organic compounds containing fluorine and carbon. Similar to the hydrocarbons in molecular structure, FCS are used in the manufacture of some aerosol propellants, coolants, refrigerants, oils and greases, synthetic polymers, etc. Most FCS are non-flammable, non-reactive, have low-toxicity, and are stable at high temperatures. However, they are suspected of causing damage to the ozone layer and their production is either banned or restricted.