15231.8 Hexamethylene diisocyanate (HDI) [822-06-0] 15232.15 Methylenediphenyl 4,4'-diisocyanate (MDI) [101-68-8] 15233.9 2,4-Toluenediisocyanate (2,4-TDI) [584-84-9] 15235.12 Isophorone diisocyanate (isomer mix) (IPDI) [4098-71-9]