ISO 16702:2007 gives general guidance for the sampling and analysis of airborne organic isocyanate (NCO) compounds in workplace air.
ISO 16702:2007 is appropriate for a wide range of organic compounds containing isocyanate functional groups, including isocyanate monomers and prepolymers. Monomers containing a single isocyanate moiety (e.g. methyl isocyanate, ethyl isocyanate, phenyl isocyanate, hexyl isocyanate) are produced during thermal degradation of polyurethanes, i.e. flame bonding and laser cutting. Isocyanate polymers, also called polyisocyanates, homopolymers, oligomers or prepolymers, are derived from the diisocyanate monomers by self-condensation or reaction with polyols. Polymeric diisocyanates are widely used in the polyurethanes, paints and coatings, and adhesives industries.
ISO 16702:2007 is appropriate for measuring any product containing free isocyanate groups. It was developed primarily for the commonly used methylenebis(phenylisocyanate) (MDI), 1,6-(diisocyanato)hexane (HDI), and toluene diisocyanate (TDI) and their oligomers and polymers. It has also been used for isophorone diisocyanate (IPDI), hydrogenated methylenebis(phenylisocyanate) (HMDI), and naphthyldiisocyanate (NDI), and their oligomers and polymers.
The method is used to determine time-weighted average concentrations of organic isocyanates in workplace atmospheres, and is suitable for sampling over periods in the range 0,5 min to 8 h. The method is designed for personal monitoring, but can also be used for fixed location monitoring by suitable modification.
The method is suitable for the measurement of airborne organic isocyanates in the concentration range from approximately 0,1 µg/m3 to 140 µg/m3 for a 15 l sample volume.