the Icynene and a piece of the old pink fiber glass insulation that was still on the floor of the attic in separate plastic bags to trap any odors coming from them,let them sit a few days then smelled them. The bad smell was definitely from the paper backing of the fiberglass insulation. The Icynene had no odor.My husband removed all of the old insulation from the attic recently ,vacuumed all dust up and the bad smell is gone. He put some wood flooring in the attic , some plywood, some particle board which I am afraid I will smell in the summer when things get hot again but so far so good.We are also installing an exhaust fan in the attic with a vent to the outside of the house so we can ventilate the attic when we want to get rid of household odors if they build up there .