Every day we are all exposed to some level of chemical fumes. When you get in a new car, the “new car smell” is largely caused by chemicals given off by new plastics. Spray paints and household cleaners give off fumes. Different plastics and wood products in your home give off odors from adhesives and finishes, especially when new. But normally these fumes are at such a low level that they cause no problems.

If you look at the comments for the article How Icynene foam insulation works, however, you will see a number of people who have become sensitized or allergic to the fumes given off from icynene insulation. What seems to happen is that these people enter the home shortly after the foam is applied (or during application), while it is still curing and giving off a lot of fumes. Their bodies get overexposed to the vapors and become sensitized. From that point on, any exposure to even a minute amount of the chemical causes a reaction. The process of sensitization can make a home unlivable for people who become sensitized…