What makes monomer Isocyanate more hazardous than polymer Isocyanate?

Answer 1

The monomer is more reactive and hazardous for two reasons. First, the monomer will have multuple reactive isocyanate groups(2-4), thereby packing more poison per molecule than a polymer ever could. Second, the lower molecular weight makes the monomer very fluid and volatile while the polymer is a solid at room temperature. So as a monomer, it has a flashpoint, gas concentration, and multiple ways to enter a person's system.

Answer 2

the unpolymerized form is ready to react and will react with more than the polymer.