This European Prestandard specifies a procedure for the determination of volatile organic isocyanates in the exhaust air of an emission test chamber after application of an adhesive. The method is based on chemosorption of volatile isocyanates with 1-(2-methoxyphenyl)piperazine (in the following: 1-2MP) impregnated filters with subsequent desorption and liquid chromatographic analysis. The method permits measurement of a wide range of organic compounds containing isocyanate functional groups (NCO), including isocyanate monomers. For testing of adhesives emissions mainly toluene diisocyanate (TDI) and methylene bis (4-phenyl isocyanate) (4,4-diisocyanato-diphenylmethane, MDI) are of concern. The method as described in this Prestandard can be used for other isocyanates too, such as isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI) - see ISO 16702. Isocyanate oligomers or prepolymers are not volatile enough to be detected in emission test chambers at room temperature.