friable

mureneva, hapero, hauras Easily broken into small fragments, crumbled, or reduced to powder.
1977, (w), The Passion of New Eve:

Spiders had woven their vague trapezes between the friable heads of dead peonies in enormous glass jars streaked with tide marks where the water had evaporated long ago.

This light, friable type of material offered excellent insulation against both desert heat and also the cold of darkness during the winter.

April 1987, Old-House Journal

It is when asbestos-containing products are friable that hazardous asbestos fibers are likely to be released and sent airborne.