ISO 17735:2009 gives general guidance for the sampling and analysis of airborne organic isocyanates in workplace air.
ISO 17735:2009 is appropriate for a wide range of organic compounds containing isocyanate groups, including monofunctional isocyanates (e.g. phenyl isocyanate), diisocyanate monomers (e.g. 1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), and isophorone diisocyanate (IPDI), prepolymers (e.g. the biuret and isocyanurate of HDI), as well as intermediate products formed during production or thermal breakdown of polyurethane.
In mixed systems of HDI and IPDI products, it is impossible to identify and quantify low levels of IPDI monomer using ISO 17735:2009, due to coelution of IPDI monomer with HDI-uretidinedione.
The useful range of the method, expressed in moles of isocyanate group per species per sample, is approximately 1 x 10-10 to 2 x 10-7.