Vermiculite is a mineral that expands with heat. It is used for high temperature insulation in attics and walls, and fire proofing of steal and pipes.  Most vermiculite sold in the United States from 1919 to 1990 was mined in the same location as deposits of asbestos. Vermiculite itself is not hazardous, but if your home was built before 1990, there may be asbestos in your vermiculite insulation. If you are concerned about asbestos in your insulation do not remove it on your own, contact Prudent Living for a consultation.