This International Standard specifies a method for the determination of vinyl chloride monomer in homopolymer and copolymer resins of vinyl chloride and compounded materials. The method is based on sample dissolution and headspace gas chromatography. Concentrations of vinyl chloride in the range 0,1 mg/kg to 3,0 mg/kg can be determined. A "dry method", suitable for PVC resins but not compounded materials, is widely used within the industry for in-house determinations. A separate International Standard based on this methodology is under development.