Which form of asbestos is considered highly friable?

• A. Sprayed-on fireproofing
• B. Nonfriable cement board
• C. Rigid vinyl flooring
• D. Asbestos-containing lagging that is cured

Answer: (A)

Friability is about how easily asbestos-containing material can be crumbled, pulverized, or turned into powder by hand pressure or slight disturbance. Highly friable materials readily release airborne fibers even with minimal handling or disturbance. Sprayed-on fireproofing fits this description because it’s a loose, fibrous coating that does not form a hard, bound matrix, so it crumbles and can release fibers into the air very easily. The other forms—cement board, rigid vinyl flooring, and cured lagging—are more solidly bound or rigid materials that resist crumbling under normal handling, so they’re not considered highly friable. They can release fibers if severely damaged, but not as readily as sprayed-on fireproofing.