Zonolite is brownish in color, about the size of a popcorn kernel, and flecked with a silvery or gold-colored metallic material, it was usually applied by pouring spaces, usually after construction. It sits loose in joists and open spaces. Vermiculite can contain asbestos. Enclosed or tightly bound asbestos fibers cause no significant health risk however asbestos becomes an airborne toxin when its fibers escape into the air during building renovations or repairs.
Why is it dangerous?