I went to my attic today and took a few pictures. Here is one which shows the "dust" that covers most of the attic (as far as I could tell, it's all over). So I would imagine this is insulation, but I'm not familiar with such.

This looks like dust but lighter than dirt. I'm more familiar with things like that yellow bit we see in the background (I think a remain of some insulation used for the ducts that the builder probably left behind).

What I'm interested in knowing is how this is called and what it's made of. Anyone knows?

FYI: The reason I ask is that I was thinking to add cabled Ethernet connections (sockets) in all rooms. Only, I did not expect to find that material. Can it be safely dug/moved around which the cabling happens.

Note 1: The house is in the Sacramento, CA area.

Note 2: The house was built in 1983.

enter image description here

  • It looks like a blown in insulation. Why do you need to know?
    – RMDman
    Oct 29, 2023 at 12:50
  • IT most likely is cellulose, which is recycled paper fiber that is chemically treated.
    – RMDman
    Oct 29, 2023 at 13:36
  • @RMDman I updated the question with the reason. I wanted to install Ethernet throughout the house and was thinking the cables would go through the attic. So now I have to find the walls through that "mess"... and wanted to make sure it would be safe to move (for me and the house). Oct 29, 2023 at 15:24
  • 1
    My... reading about blown attic insulation. It sounds more complicated than I thought... but it otherwise looks safe. Oct 29, 2023 at 15:42
  • How thick is this "dust"?
    – RonJohn
    Oct 29, 2023 at 21:43

2 Answers 2


Based on a fuzzy picture from far away, possibly vermiculite, which is steam-expanded mica, and some of that does have asbestos contamination. (It's not mostly asbestos, but the mica has some percentage of asbestos co-located with it particularly from one mine.) Which is not a big deal with proper personal protective gear and a shred of common sense. Use a dust mask or respirator, wash clothes & take a shower. That was more commonly done as "loose fill" rather than "blown in" - not that it matters at this point.

Cellulose (fire/bug treated paper fiber) is usually a bit less granular than this appears to be, and doesn't have shiny spots from the mica being at the right angle to the camera; it's not a great picture for identification purposes, but I seem to see both of those things.

The EPA has (what I consider) both reasonable and histrionic advice on the subject. Choose your own adventure.

Based on additional description in comments, probably cellulose and I'm being mislead by camera artifacts. Shovel or sweep it out of your way while working, and back when you are done working. Wear a dust mask anyway. Consider adding more when the cabling is done (insulation recommendations have increased significantly, along with energy costs, since 1983. Cellulose is cheap and effective insulation.)

  • To the touch, it feels more like cellulose. Very light and very small particles. It sounds like vermiculite is harder and larger bits (according to the pictures from your histrionic link). Oct 29, 2023 at 16:31
  • That is correct, and the histrionic link does have good ID pictures. Cellulose is more innocuous, but a dust mask is still a good idea (no point in taking on additional dust in the lungs, even it's mostly harmless.
    – Ecnerwal
    Oct 29, 2023 at 16:34
  • I took a few more pictures at that time, but the insulation material is blurry on all of them. I suppose that's how the auto-focus works. Since I need the ladder on the outside to reach the attic, I'll pass in trying to get a better picture at this time... Oct 29, 2023 at 16:35
  • 1
    Not a problem - your more detailed description makes cellulose the more likely, and outside access should make it easy to keep the dust out of the house.
    – Ecnerwal
    Oct 29, 2023 at 16:36

With the proper eye and breathing protection it is safe to move to drill plates and run your cable.

If you want to know if it contains any asbestos, you must have a lab analysis.

It is just practical to vacuum off any debris clinging to your clothes and wash up. (I know this is basic,but there are some that cannot do anything without being directed.)

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