Thin and very straight fibers have been appearing in household dust, primarily in the room which I occupy. I suspect these fibers to be fiberglass. These fibers shine/glint back if illuminated with a strong light source and are of varying length (<1mm to 6-8mm). These fibers appear to be consistent with a sample of fiberglass yanked from the attic. I noticed these fibers in the dust in my room about a month ago. A spot check of dust in other rooms shows similar fibers, though in a much smaller frequency.

A member of the household fell through the ceiling walkway above my room ~2.5 months ago, which pushed a lot of insulation through (and very probably dispersed it through the room). The process of fixing the hole also probably dispersed a bit of fiberglass insulation through the room. I suspect this to be the primary source of this contamination, but I can't be entirely sure.

I've cleaned the dust from the room thoroughly about twice a week (wiping down all surfaces with a wet microfiber cloth). The longer fibers seem to be appearing more rarely, but the smaller ones seem to still be appearing with some frequency.

I have a few related questions/concerns:

  • The particulate does not seem to be very dense in the dust, but it is noticable (especially in my room) with a flashlight. I spend a lot of time in my room for both work and leisure purposes; I typically sleep in my room, but have moved to sleeping in a different room in light of this issue. I haven't really noticed any changes in my respiratory patterns. I suspect this to be a health hazard in the long term; is this accurate?

  • Is this likely to be continued contamination from the ceiling incident, or is there another source of contamination (e.g. poorly-sealed lighting, poor/drafty attic entrance sealing)? There are 5 possible sources for contamination in my room which I can spot: 4 light fixtures and a central air vent. Light fixtures in the room are IC-rated, but I am not sure how hermetically sealed that means they are. I suspect the contamination is not through the vent, as these particles would then appear more frequently in the rest of the home as well.

  • What's the best "one and done" way of removing as much of this contamination as possible, assuming that the source of contamination is not still present (i.e., the particles were a one-time contamination from the walkway incident)? The room is carpeted (though we have long wanted to replace it with a hardwood/laminate). I have a HEPA air filter (a Winix C555, a relatively low-end model which has "multi-stage" filtering with a "true HEPA" filter) which I run fairly continuously on a low-medium setting (though I suspect that this may just be continuing to "juggle" the particles through the air). I can vacuum and dust the room more often as well, potentially daily.

Thank you in advance for reading my post, and for any advice or help you may provide.

1 Answer 1


Many of have worked in attics without masks over the years at hundreds or thousands of times the exposure you are getting but I won’t say it’s not a health issue but I am not aware of any issues with such a light exposure.

Other areas to check include the duct work. Metal trunk ducts usually have a fiberglass blanket that is foil backed. If someone tweaked the trunk line they may have disturbed a seam and created a Venturi that is pulling some fibers in, I bring this up because a home owner sat on his trunk line and it pulled in quite a bit but I was able to seal it up, since the ceiling was down you may have not noticed.

Flex duct (usually black plastic inside and outside with insulation in the center) could have pulled loose and exposed the fiberglass on the inner plastic a flashlight would show yellow or pink fiberglass if this happened. Other than that sealing the fixtures would be the areas to look at if it’s not showing up in other rooms of the house. As I said I am not aware of any issues with such low levels but there may be a stuffy out there that says it is dangerous, asbestos was once thought to be safe along with the Hindenburg.

  • I also don't know the details of how bad fiberglass is but do know that there is a BIG difference between the affects of fiberglass and asbestos on the body and it has to do with the shape of the fiber. Fiberglass is straight and smooth (it's glass and has a glass surface that we know) while asbestos has 'hooks' and other shapes. Asbestos gets embedded and trapped and the normal body processes can't remove it. And on top of that it is continually irritating the same spot.
    – Ack
    Commented Apr 3, 2020 at 22:42
  • Thank you both for your feedback. Commented Apr 3, 2020 at 23:09
  • I'm a little less concerned, but would still like to get to the bottom of this. I'm going to take a look up top and see if the ductwork is impacted. Should I be looking at the IC-rated recessed lighting enclosures as well? Commented Apr 3, 2020 at 23:20
  • If just means in contact, not how well they were installed if you have loose fill and a sloppy install yes some could be coming from them.
    – Ed Beal
    Commented Apr 4, 2020 at 8:43

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