TDI Isocyanate is used for flexible foams (for slab stock or block foam at mattresses and automotive seats as hot or cold mold technologies). TDI iso is a reactive chemical. TDI’s isocyanate groups (NCO) can be reacted with polymers that have alcohol (–OH) groups to make polyurethanes.TDI-based products are commonly used in automotive seating, furniture foam applications, mattress cushioning, and specialty foam applications