VOC = Volatile Organic Compound.  The term “Volatile Organic Compounds” refers to organic compounds that readily evaporate. VOCs include pure hydrocarbons, partially oxidised hydrocarbons, and organic compounds containing chlorine, sulphur or nitrogen.

They are widely used as fuels (e.g., propane and petrol), as paint thinners and solvents, and in the production of plastics. VOC emissions have to be carefully controlled so as not to contribute to air toxicity and urban smog.