friability

The ability of a solid substance to be pulverized or crumbled with little effort. A friable substance is any substance that can be reduced to fibers or fine particles by a small pressure, such as inadvertently brushing up against the substance or breaking down the substance by human hand. The fibers and small particles then become dislodged and released into the air where they can be inhaled.

Examples of items containing friable asbestos include: acoustical plaster, insulation, paper products, pipe coverings, rollboard, spackle, and patching compounds.

Materials containing non-friable asbestos cannot be easily pulverized by hand. Examples include: asphalt and cement roofing products, base flashing, asbestos cement, siding, vinyl asbestos floor tile, packing material, gaskets. However, these materials can become friable if they are damaged, sanded, cut, or drilled into.