friable

adjective4

1. •
   Easily broken into small fragments, crumbled, or reduced to powder.

   • 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. — 1977
2. •
   Of soil, loose and large-grained in consistency.

   • Sand has been incorporated to make the soil more friable.
3. •
   Of a poison, likely to crumble and become airborne, thus becoming a health risk.

   • It is when asbestos-containing products are friable that hazardous asbestos fibers are likely to be released and sent airborne. — 1987
4. •
   Of a number: smooth, that factors completely into small prime numbers.