Original: The great majority of phosgene is used in the production of isocyanates, the most important being toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI).
Simplified: Today, most phosgene is used to produce isocyanates. The most important isocanates in this context are toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI).