photo of resin binder on fiberglass insulation fibers Airborne Fiberglass Dust Hazard FAQs
Q&A about indoor airborne fiberglass / dust

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Airborne fiberglass dust hazards & the role of particle size in particle detection as well as in health risk assessment:

Most buildings Probably have Mostly Large Fiberglass Fragments. Prudent Avoidance of Fiberglass Insulation Dust makes sense.

This article provides information about fiberglass fragments and indoor air quality fiberglass contamination issues in residential and light-commercial buildings.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Airborne Fiberglass Fragment Hazard FAQs

Home made return duct using fiberglass insulation (C) Daniel Friedman

Questions & answers about fiberglass particles in indoor air, posted originally at FIBERGLASS FRAGMENT HAZARDS in AIR or DUST

On 2017-10-29 by (mod) - do not stuff fiberglass in return ducts: fire risk

NO Vern.

Do not stuff fiberglass insulation into a return air inlet or duct.

Stuffing fiberglass into a return duct

1. risks drawing insulation into the blower fan where it can cause overheating and even a building fire! This is UNSAFE and risks FIRE.

2. blocks return air, preventing the heating system from delivering heat where it should

3. risks blowing fibrerglass fragments onto building occupants - creating an indoor air quality problem

On 2017-10-29 by Vern

Is it safe to stuff return/fresh air duct with fiberglass (stuffed inside)?

On 2017-04-13 by Amy


We had a crew not do such a great job removing water damage from our home. They left wet fiber glass insulation in and decided to put fans on it, which just pushed around fiber glass particles into the air. Also they did not cover the return vent.
Currently the furnace is off and just the air scrubber and dehumidifier are running.

I have a 9 month old child and i worry that the furnace filter would not be able to remove the fiber glass particles brought in by the return vent. Is this a high risk to our child? what steps do you recommend to mitigate this? Is it dangerous to keep a child in the house under this situation?

On 2017-04-10 by Anonymous

Hello again .I looked at the links you sent but my landlord won't take any further action .i be been trying to live in my flat for three days another attempt to see if I can cope .but I'm having to constantly spray walls and ceilings and floors with a large pump sprayer mister every hour to damp it down .as I said I painted walls with pva to try to seal any in ,I keep my clothes in a cupboard and the bed covered in plastic .

.I just have my bed a chair my laptop and that's it as anything else in here is just another thing I'd have to wash down.
I can't really see any sparkly bits anymore but I'm still feeling the horrible irritation on my face .as soon as I walk in after being out .or after I've damped it down and it dries out and starts to circulate again..and I've noticed it too ,as soon as iI walk in to the main entrance to the flats in the foyer ..

not a lot but enough to know it's in the whole building..of I don't damp it down I get covered in it and and it's unbearable .maybee I'm just allergic to very tiny microscope dust and no one can do anything .It doesn't happen anywhere else I go. ie,, other people's houses etc just my building and my flat ,

can the particulates be so small that you would need a microscope to see them and these are what is causing me so much distress ?

Thank you for replying and the links I think I need to speak to a scientist who could maybe understand what is happening .sorry if this all sounds mad but I'm living in it and don't know what to do ,

even friends that understood initially and actually saw the dust and felt it too on their skin and said it was really bad and they couldn't live in it ..are now saying that maybe it's in my head .because it's not very visible much .sincerely Robyn .

On 2017-03-23 by (mod) -


Large glass fibers such as constitute most fiberglass insulation may be an itch issue but according to industry-studies are not considered a high health hazard. On the other hand small fragments such as may be produced by walking on fiberglass overyears or chopping it up by some accidental means (falls into a fan) can be a more serious health hazard.\

IN any event if you're sure that there is an unusual amount of anything in house dust in your home it makes sense to find the source. If the source is ongoing then cleaning alone won't be adequate.

You might find by contacting RICS (Royal Institute of Chartered Surveyors) an inspector who is familiar with these issues and who could help you out.


On 2017-03-23 by anon

I forgot to mention that I cannot open any Windows to get air in as this is where it's coming in from so not feeling that well .

On 2017-03-23 by Anonymous

Thanks for your reply.
Well I've just spent my first night in my flat
Sleeping on a blow up plastic mattress and low and behold I'm itching again..

.I've not brought much into the flat just some clothes which I'm keeping in a plastic box and a kettle and few bits to survive a day as didn't want to contaminate anything else I checked last night to see if I could see any tell tale sparkling ,,and there was on the air bed ..

I do this with my phone light which shows it up well, I've been doing this for months and praying that I don't find any any way I now feel I'm back to square one and it's got to start all over again with me living in it ..just so tired and depressed .what can I do ?

Do you think if I bought a load of disposable floor wipes and wiped down everywhere .that this would help at this stage.
Obviously it's not as bad as it was but I'm still itching and can feel it on my face as I walk about the flat..or disturb the air...

I thought painting all walls and ceilings with the pva would have gotten rid of it all ..
I have a pump action large garden mister that I use to damp it down in the air so I can wash it off the floor ....

my eyes are sore now and my feet are itching as I've been walking around like you do but hey never mind ..I will continue to try and get this under control and hopefully all out and totally free of the dust just want my life back but totally all focused on this as what else can I do .

and just to add insult to injury the folks round here in my block think I have a psychiatric problem and I've imagined it all ha ha ha as they saw the men come to replace the wall insulation in their protective suits etc and where told that it's all fixed and ok and that I threw all my stuff out as I'm not really very well

I live in the UK ..people here don't seem to be very up on this subject of glass fibre dust ..I don't know why ...this is why I'm on your site as there is nothing like this here .cheers for reading.

On 2017-03-19 by (mod) -


What you describe sounds awful to me too, though I suspect it was an unnecessary hell or at least premature hellinization since I don't see that there has been an accurate on-site inspection and diagnosis of the problem.

Typically you

HEPA Vacuum
Damp Wipe

and find and fix the problem particle source

On 2017-03-19 by Anonymous

Hi .I have just spent 5 months of hell ripping up all carpets disposing of all my belongings clothes linens soft furnishings and actually having to gutt my home and then literally having to hose down my flat walls with a hose pipe and suck up with water with a vax wet an dry Hoover .

and then try and paint all walls with a mixture of pva and try to get rid of a massive influx of glass fibre dust which blew in through vents above all of my Windows through out my flat from old cavity wall insulation ,

minute particles you could see sparkling over everything and it drove me insane with itching all over and coughing and constantly battling to get rid of it all.

my landlords did not believe me and did nothing .then it took me having to see a doctor for them to call in a company who replaced the cavity wall insulation and arrived masked up and in protective suits to suck out the old stuff.nothing was done for me in the flat .just a couple of men who went in and hoovered the carpet ( that was still there at the time) with an old conventional household Hoover!!!!! Then I was told all clear to move back in!!

..It's a housing association flat so I had no choice but to try to clean it myself as they are not willing to admit that it was a problem..I'm still itching when in there and am going to have to move in soon .my question is how could I have cleaned it better so there is none left as it's still sparkling in places after months of being soaked and the water sucked up and everything washed .

Oh by the way I cannot open the vwindows as it is still coming in from vents directly above it seems to be getting sucked in and you can see it on black plastic that I have put on Windows sills inside to check if it's still coming in .

On 2017-02-14 15:34:53.902623 by Anonymous

i found a bat of fiberglass left over for years under the suspended floor. there was many gaps in the floor at this very place that I have sealed. Problem is there are many other (plumbing) gaps in the floor and else so i am guessing particles find their way somewhere in tiny holes with the draught effect..

On 2017-02-13 by (mod) - old fiberglass insulation removed from the attic which left us with high level of particles floating in the air.


If there is a consistent and unusual level of airborne particles that would be odd - I would look for the source, perhaps starting by checking settled dust to see if the problem was you've missed an area of cleaning such as carpets; else there's a particle source to be found (check for damaged duct insulation, for example)

On 2017-02-13 by Nolan

i had old fiberglass insulation removed from the attic which left us with high level of particles floating in the air.

For months of constant floor/furniture cleaning, I still keep finding shinny glittery of silver sometimes red color particles. This is most noticeable when emptying the water bucket i can see that particles remaining.
while it does not all the characteristics of fiberglass .. what could this be ? thanks.

On 2017-01-13 by (mod) -

Good question, Lindsay - I don't know an authoritative answer but I suspect from having worked around fiberglass insulation that it's the larger particles that are so irritating to the skin and the smaller ones that are more likely to be inhaled deeply into the lung.

What confuses some people is that even after washing clothes and bathing vigorously some skin irritation may continue if you've had an acute exposure to fiberglass debris. I think that's because you've already irritated the skin by making micro lacerations.

If there is a high level of fiberglass dust indoors it makes sense to damp wipe and HEPA vacuum to clean the area. While fresh air ventilation is generally good for diluting indoor air contaminants, if there is a significant dust-particle reservoir it makes sense to do some cleaning first rather than just blow the dust around.

I'm sorry that my referrals were dead in the water - that's disappointing.

On 2017-01-13 by Lindsay

I know that the tiniest (more risky) particles are rare from what you said - Would one get similar symptoms and skin irritation from those sized dust particles or just the larger ones? Would you know if either size are in your clothing/belongings from irritation or not necessarily?

In general - whether fiberglass count is high or average or low in a home or apt - is it better to have ventilation - open window - or does that just blow it around?

Baxter rand Wayne didn't get back to me, Flappan doesn't do it, and EMSL is not offering much. Any other recommendations?

Thanks again!

On 2017-01-09 by (mod) -

Not necessarily fiberglass.

And yes I always find at least a few fiberglass fragments along with other common house-dust particles in most indoor building dust samples.

On 2017-01-09 by Lindsay

Got it, thanks. To the second part of my question (re: looking at dust with a flashlight in dark) - If you see pieces of dust that shine/glitter (when you hold the light a certain way and look very closely), is that always fiberglass dust? Is this a reliable method of gauging it? Is it normal to see some in dusty areas, on clothing, and on the back of a TV or computer screen?

Thanks Again!

On 2017-01-09 by (mod) -

Of course we both understand that I cannot inspect your home by e- text, and that an expert on site will always find things that neither you nor I were considering.

With that apology stated I suspect that the total volume of insulation that was handled ripped and stuffed going around electrical outlets was trivial.

However my opinion is it was not the most effective way to insulate in those spots because it's really tough to stuff in a reasonable amount of insulation into a wall with that method. Better would have been to use a fire rated insulating foam spray.

On 2017-01-09 Lindsay

Addendum - Someone had suggested turning the lights out at night and going through my apartment with a flashlight. I just did so. I am finding glittering pieces - particularly on the back of my TV. I just saw "one glitter" on my couch. It is also interspersed with some of the dust on a shelf that hasn't been dusted in a while.

I know that some fabrics naturally have a glitter - but I am seeing it on one sweatshirt (which sat out to dry) and a tiny bit on some clothing. Is this a reliable method?

Are my findings typical? Is there a way for met to gauge what would be above normal? Are these glittery pieces that become visible with the flashlight typically the dangerous, tiny type of fiberglass?

Thanks for all of your knowledge and expertise. Two more quick questions:

-In addition to the issue described with the insulation in the PTAC sleeve....

When I first moved in a few months ago, they needed to insulate my outlets. The worker came up with a yellow fiberglass roll and tore off pieces like cotton candy - no protective gear.

I was home both times. Based on your last response, would this type of mechanical damage be of concern? (I did get a piece lodged in my skin at that time - I didn't know what it was back then.)

-It sounds as if you think the light tapping and taping recently done in the heating/ac sleeves would not have created dust (I had been concerned that it might have gotten into the blower). I have just noticed a tiny rash on my knee which is now concerning me. I have reached out to the labs you listed.

Until I get a response, are thee any signals or things that I can look for in my apartment to identify whether fiberglass dust has gotten into my furniture, clothing, belongings?

Thank you.

On 2017-01-05 by (mod) -


The fiberglass conditions that produce high levels of small particles in cases I've seen are not specifically age but rather mechanical damage such as having been walked-on in an attic floor.

On 2017-01-05 by Lindsay

Thank you very much. This is such helpful information. There is typical pink fiberglass (could be up to 8 or 10 years old) in the sleeve under and around my two heating a/c units (PTAC/HVAC in an apartment unit in a large tower). The insulation was never sealed/taped up and was exposed under the units. There is also cold air felt pulling in a bit through the sleeve. I am wondering a few things:

-Could there be breakdown (with the age of the fiberglass and exposure to the hot/cold), and could the smallest type of dust particles have come from this and could they have floated directly into my apartment?

-We sealed up the larger unit and only part of the smaller one recently. Could lightly touching the fiberglass insulation with a hand while taping it back create the dangerous kind of dust and send it off into the air (it was somewhat enclosed in the sleeve - but could have floated forward where the unit was wide open with the front cover off).

-If the wind or our touching created the dangerous kind of dust and it settled on the floor in front of the sleeves, could it now be pulled up into the a/c heating unit blower on air intake? (The units have fiberglass filters at the bottom, but my understanding is that those filters don't capture small fiberglass particles).

-Would there be a way of knowing if my furniture/belongings have been contaminated with fiberglass dust?

Thank you very much!

Since it is old and exposed to hot and cold air, could tiny

On 2017-01-05 by (mod) -


After decades of field investigation and forensic lab work, with exception of a few pro-bono or research assignments, I have retired from field work and also from forensic laboratory analysis work to concentrate full time on pure research and writing for

At we provide extensive free public information about building & indoor environment troubleshooting & repairs. We also very much welcome questions, critique, content suggestions concerning those topics.

You are also welcome to send me specific questions, suggestions, photos, reports by email, and I'll be glad to comment as helpfully as I can.

Environmental Test Labs:

For environmental or forensic investigative support and lab work, you can use any forensic lab provided you first check that their area of expertise matches your needs.

For strange particle analysis, building dust analysis, fiberglass particle screening, mold contaminant screening contact these expert forensic microscopists

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For mold or general environmental dust samples also contact our backup

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EMS lab is a very large and competent network of labs offering a wide range of services is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information for the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.

On 2017-01-05 by Lindsay

Is there a lab where one can send fabrics or dust samples if there is concern about fiberglass dust contamination?

On 2016-12-04 by Jaine

Please excuse my typo. I was asking should we be using masks?

I have been working for a emergency restoration company for over 2 months but I strictly do fire mitigation. I've had to handle wet/dry insulation that has fallen and been thrown around fire fighting crews, inspectors, homeowners, etc. we recently started on a house built in the 60s or 70s where the kitchen ceiling had to be torn out.

My crew had to remove any white blown insulation that could be contaminated by smoke or moldering. I noticed at the end of the day where the sun was shining through in the windows you could see sparkles floating with dust. my face was also beginning to itch and burn.

I now have broke out with painful hard red sores that are itchy and hot to the touch on upper body and my chin. My questions are could my symptoms be caused by fragmented fiberglass and she we be using masks?

On 2015-11-25 by (mod) - An ordinary vacuum cleaner will actually increase the level of very small airborne particles, look for HEPA vacuum cleaners


An ordinary vacuum cleaner will actually increase the level of very small airborne particles, unless the vac

1. is HEPA rated
2. has no significant air leaks

I've never heard of CPA -rated vacuuming or vacuum cleaners and could not find a reference to such a device. Maybe someone mis-spoke, or perhaps a reader who has heard of such a system will use our page bottom CONTACT link to give us a hint.

All homes I've ever tested had some detectable level of fiberglass. It would be a conceptual error and a financial one to seek a "fiberglass-free" home.

On 2015-11-25 by Jake - what is CPA vacuuming?

What is CPA vacuuming? I tried looking it up but had no luck.

I've been using a shop-vac with a HEPA filter and wiping stuff down after spraying it with a water bottle. I find that duck tape works good on some fabrics too.

Am I being overly paranoid? Do most homes have some Fiberglass in the dust? How important is it to cover exposed insulation? I have a few spots in my basement that the insulation is exposed, a few spots on wall etc (perpetually unfinished basement)


On 2015-11-23 by (mod) -

Frankly opinions that being exposed to fiberglass improve your immune system sounds like nonsense to me. If you are concerned about the presence of large and small fiber glass fragments in your present environment your clean up would benefit from using a CPA vacuuming.

On 2015-11-22 by Jake

The Fiberglass that was spread through my house wasn't regular pink house insulation. I don't know much about it other than it was white and Fiberglass from work, probably from the 70s. It was brought in on clothing mostly because they had been cutting it off of piping etc.

The doctor I brought it up with basically said that if anything serious comes of it I probably won't know for at least 20 years and he suspects that I'm not at much risk because I'm not working with it my whole life. Short-term exposure vs some people with long-term exposure I suppose.

To make matters more frustrating, I've moved and have been slowly cleaning out the possessions of mine that I have not thrown away, but I have an aunt and uncle who work with Fiberglass mat/cloth and visit often and every time they leave I notice more of the stuff on my furniture etc.

They vehicles are FULL of it too. Seems I cannot escape the stuff. I'm not sure if I'm being overly paranoid or if this is actually as serious as I make it out to be. I finally confronted them about it and was met with the reply "It's not like the old Fiberglass.

This stuff breaks flush and not jagged.

Plus it's all big strands so it doesn't become air bourne. If it was a hazard do you think I would bring it into my home?"

And then he went on about how our bodies and lungs are very good at cleaning themselves and removing impurities and how being exposed to Fiberglass occasionally is more likely to help your body build a tolerance and keep the immune system active. I can understand the large strands part but the rest doesn't sound right to me. What are your thoughts? Thanks

On 2015-11-10 by (mod) -

Jake the Cancer risk from fiberglass is not something anyone but your doctor or you with a specialist in environmental medicine can assess and I suspect it's person-specific.

In general, much research argues that fiberglass is not a carcinogen, but that research seems to me to be focused on large particles - which are indeed less of a risk: they don't get inhaled as deeply into lungs and may be expelled.

But in my OPINION there are possible health risks from very small fiberglass fragments, maybe down in the 1u range or less. The good news is that most building fiberglass insulation, ducts, ceiling panels, etc. don't produce a lot of these tiny fragments.

When I've found tiny fiberglass fragments in the lab it's principally been in environments where normal fiberglass products have been abused by foot traffic, mechanical maceration or other rather extreme activities.

Let me know what your doctor advises.

On 2015-10-19 by Jake

Hello. I lived in a home completely contaminated with Fiberglass dust for 4 months.

My workplace also had a lot of open Fiberglass insulation and air circulation. Am I at risk long-term for cancer or any other serious ailments? It's been a slow terrible process for me cleaning all my life's possessions and getting rid of many items.

The fibers spread through the entire house and was visible on everything. I'm sure I breathed in a fair amount, especially in the last month when it got really bad

On 2015-09-27 by Anonymous

IMO if the fiberglass lined duct is damaged it makes more sense to replace it than to add filters. If it intact the airborne fiberglass levels ought to be trivisl. Also review our nites on particle size.

On 2015-09-27 by Roxanne Wolffe

I have been told that, provided there are filters in all the air returns (?) throughout the house, the main air intake handler does not need one. I have also been told that the main air intake does need a filter because it draws air in over the insulation and will directly deliver it into the house air environment.

I tend to believe the second because I see white fibers floating (drifting) around often AND bith my service dog and I seem to be sick quite often if not always with skin issues and sinus problems.

The house is roughly 3 years old, and thrown together hastily in my opinion and things such as a filter in the main air intake was never done and I wasn't informed until 2 years later (different topic for another posting!)

So, which is it?

On 2015-03-19 by (mod) -

Anon: about fiberglass boat manufacture hazards see your question and our reply in the article above.

Other readers, Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies,

Question: is it possible to remove all of the fiber glass particles from my home?

Due to improper air duct cleaning and not re sealing the ducts we now have fiber glass particles on everything in my condo. The air quality is horrible. The particles are floating in the air.We had a well qualified inspector to inspect this calamity and he said everything has to be heppa vacuumed and the walls have to be washed down with a product.Clothes removed and washed or cleaned.

The fiberglass got into clothing, furniture, every single thing. I have moved out until the clean up is done, question: with the proper clean up company, which i believe we have, is it possible to remove all of the fiber glass particles from my home? Thank you so much for an answer. - L.S. 9/14/2014


No it is not possible or at least not feasible, nor is it appropriate to try to remove literally all fiberglass particles from a home - certainly not in normal circumstances. Small amounts of fiberglass are almost always found in buildings as there are various sources.

But it is possible, following the advice from your paid expert, to remove abnormal levels of fiberglass by extensive and proper cleaning, getting things back to a level that would not be expected to lead to occupant complaints traced to fiberglass.

Don't set a target of zero of any particle in a building. You'd be inviting price gouging and you're setting an unreasonable goal. Even in a computer chip manufacturing line where air is HEPA filtered and workers wear Tyvek clothing, and booties, and enter and exit by means of an air lock, the airborne particle level still won't be zero.

Question: hazards from power-washing a fiberglass roof

(Jan 9, 2015) Anonymous said:
would like to know what kind of repercussions can occur from being exposed to individuals cleaning a fiberglass roof power washed and all the debris flew into grass area and into outdoor gazebo covering furniture hanging plants etc.


Anon from just your note we can't know the fiberglass particle size, airborne levels, proximity, or exposure level. It my OPINION (I am not an industrial hygienist) there is a POSSIBLE respiratory or skin or eye hazard ... it depends on the actual exposure, particle size, duration and perhaps individual medical conditions.

A Google Scholar search performed on 3/19/2015 did not find research citing "fiberglass roof hazard"


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