Could your ductwork be dirty? Do you know when it was last cleaned.

I would get some QUALIFIED people there to look at your situation. Firstly, what is that material? Also, even if the material is not a hazard, dust of the magnitude you're describing could not be good for anyone.

Is the material only in your attic? If so, and it turns out to be rockwool or other useful material, it seems there are leaks in the house that allow it to be transmitted into the house. It may be that the vapour membrane does not provide a continuos barrier. There are also cracks and joints which have to be sealed. Here's a attached link which shows the type of areas you should look at. Click on the pictures. There's attic hatches that are not sealed properly too. This may be what is going on, per your comment "I'm thinking the dust is from the insulation being pulled from the attic by our heating system."

Ted

Here is a link that might be useful: some sealing details

It's likely the insulation is cellulose. Look at the link in my post on this page "cellulose/rockwool?". There is a lot of info there re properties, safety, etc. It is a good material. Materials like fiberglass, and others, can cause more problems in regard to their dust/shards and properties.

Ted

I think it is cellulose from the pics and video I've seen. From what I have read it is a good insulation...so we really shouldn't remove it, I guess.

Our ductwork is not the cleanest, I'm sure, but even when we have no heat or air on our house is still quite dusty. So I don't think it is just from dirty ductwork. I even put cheesecloth over the vents and that didn't help. I thought perhaps the cheesecloth wasn't dense enough so I bought filters for all the vents...same results. Our walk-in closet in the master bedroom has the attic access in the ceiling. Our clothes get dusty (no vents and the door stays closed but there is a crack at the bottom) so we taped around the access and that has helped.

Thanks for the info! I'll be checking to see if there are anymore words of wisdom on this subject.

peggy,

Re-read my previous message. I refer to proper sealing. You may be satisfied that the insulation material is OK, but it is important that you also have proper sealing. In our old houses there are areas which allow major leaks into and out of the house. In winter the heated (you're paying for it) air leaves the house. In summer the hot humid air enters the house. In summer and winter, any breeze blows drafts in and about the house. You may have insulation in your attic and walls, but the drafts blow right through that (even fiberglass is totally porous), unless it's solid or a closed cell material. Even with solid materials, if they are not sealed around the perimeter to adjoining structure, the drafts will come through.

You should check under the cellulose in your attic and determine if you have competent vapour barrier. This may be plastic film (or building paper, which is not a vapour barrier, but will provide a draft barrier) and it should be sealed with sealant at the edges and laps should be taped. Penetrations such as vents, around ceiling fixtures, etc should be sealed.

If you do not have the vapour or draft barrier at all, or if there are leaks in it, the cellulose, fiberglass or rock wool particles will be pushed through all of the joints, cracks, edges, penetrations in the attic floor and edges and into the house, even travelling into the walls and out under the baseboard and electrical receptacle openings. I mentioned your attic hatch, which should also be insulated and sealed (like your door weatherstripping).

I know this is all too much, but that is the case. You can put up with as much of the deficiencies in insulation and sealing, or you can take some measures. It's not life threatening, but it does make a huge difference in comfort and quality of life and energy savings, not to mention health and nuisance factors (your dust for instance). This is not just theory, but also proven by people who have done even some of the measures and realized payback.

I am in the same position as you. I only have 4 inches of cellulose in the attic and will have to increase it, likely with batts of fiberglass or rock wool. Before I do that, I'll have to peel back the cellulose to see how good the sealing is. I may have to pull all the cellulose and replace the vapour barrier. I'll seal the penetrations.
My house, particularly the second floor bedrooms are extremely warm in the summer. The cause for that is likely requiring more energy use in the winter. I don't know what your situation is, or if the dust is your only concern.

I'll be happy to give you more information as to details, but only if you are serious. I am very busy.

Ted