How to Know What Insulation is Behind Your Walls

In 2001, the World Health Organization removed fiberglass insulation from its list of possible carcinogens. However, if you're handling it, you need proper protection, as microscopic slivers of glass can break loose and irritate your skin and throat, says Allen Rathey, president of the Healthy House Institute.

If you have it: Avoid disturbing the material. If you have to work with it—to fluff up batting that's been flattened, for example—wear gloves, goggles, a dust mask, and a loose-fitting long-sleeve shirt. Make sure to clean up thoroughly afterward.