Identify this material

I was inspecting a house here in Southern Calif., the house was build in the late 60’s. In inspecting the attic, the insulation that I found was laid in and is a fiberous white and brown material resembling cotton and wool. I do not believe it is asbestos but I want to make sure. Anyone have experience or can identify this material. Just as an added note, the heating/cooling ducting was covered in the asbestos corrgated material.


Some additional information. When I held the material out in direct sunlight, the white material was fiberous and looked like spun glass. The brown material looked like paper or wood. When I took flame to it the brown material burned off and the white material turned black. Any thought or insights would be most helpful.

Sounds like a mixture of loose fill fiberglass and cellulose.


The brown stuff looks like rockwool and based on your description, the white stuff could be Amosite (which contains asbestos).

Do you know the answer, or are you looking for an answer? If you’re looking for an answer, I would caution that it may contain asbestos and recommend that it be verified through laboratory testing.