Is skin absorption a significant exposure route for diisocyanates? MDI. Floor screeding. No. No. F. TDI. Block Foam blowing. Yes. Yes. G. TDI. Moulded Foam . research using our state-of-the- art scientific laboratory in. Health aspects of MDI and TDI have been subject to intensive research, . may promote absorption of the diisocyanates through the skin and into the body.