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Collapsing concrete hotel, La Manzanilla, Mexico Pacific Coast © Daniel FriedmanConcrete Dust & Odor Hazards
Track down the source, evaluate, & cure concrete dust & smell complaints in buildings

Concrete dust & odor hazard source tracking & remedy: this article describes odor & dust complaints traced to concrete: new pours, sawing or cutting concrete, substances spilled onto and absorbed into concrete, and other concrete or masonry-related odor and dust hazards.

We include citations of expert sources on concrete dust exposure hazards, and we discuss how to deal with odors from wet or contaminated or spilled-on concrete floors or walls.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Concrete Odors, Smells, Dust: exposure hazards, sources, remedies

Expansion joints in a new poured concrete floor slab, Tucson AZ (C) Daniel Friedman at ODOR DIAGNOSIS CHECKLIST, PROCEDURE we introduced the concept that while concrete itself is not normally much of an odor source once it has cured, people may observe or complain of "concrete dust" odors in buildings where concrete dust is present, especially when combined with moisture.

[Click to enlarge any image]

Reports of concrete dust odors are particularly likely near concrete cutting operations - a situation that may present an airborne particle hazard.

We have observed a similar odor traced to airborne dust in an area of heavily-trafficed cobblestone-and-concrete streets at the onset of rainfall after a dry spell.

Concrete Absorbs Spills, Animal Urine, Odors, Even MCOCs or VOCs

Other "concrete odors" may be traced not to the concrete itself but to substances that have been absorbed into the concrete, such as animal urine,chemical spills, or cleaning products.

For example, leaving a dog or cat shut in a garage or basement where there is an un-sealed concrete floor eventually means you will want to consult

ANIMAL or URINE ODOR SOURCE DETECTION and

then ANIMAL or URINE ODOR REMOVAL

At VINYL SIDING or WINDOW PLASTIC ODORS we include a case report of an un-sealed concrete floor absorbing odors from nearby outgassing plastic siding & windows, trim, or soffit materials.

Concrete floor cleaned & sealed with a clear finish leving marks of prior tile installation (C) Daniel FriedmanOur photo (left) illustrates a clean and seal approach to an old concrete floor in a building now used as a restaurant in Poughkeepsie, New York. Vinyl-asbestos floor tile was removed and the floor was cleaned and sanitized.

In a final step the new owners polished then sealed the concrete, leaving old stains in place as a point of interest that shows the building history.

The general approach to curing an odor traced to a spill on raw or un-sealed concrete involves these steps:

  1. Clean the surface using a non-sudsing detergent such as a TSP substitute
  2. Rinse the surface thoroughly removing both loose dirt and the leaning agent
  3. Remove all standing water, e.g. using a shop vac.
  4. Dry the surface, using fans and perhaps a dehumidifier if the surface is indoors.
  5. Seal the surface: when the surface is dry enough (below 12-18% concrete moisture level) you may need to apply a sealant or a sealant followed by a finish surface of expoxy paint, concrete floor paint, or a finish floor surface such as ceramic tile.

    Also see AIR QUALITY STUDY San Miguel de Allende where we are studying airborne the entrainment of airborned dust and debris during rainfall in a seasonally dry climate.

Do we always need to seal the concrete slab or wall? No.

In contrast with the re-sealed slab-on-grade concrete floor shown above, our wet basement cleanup and repair photograph at below left was a different matter. A crack in the building's foundation wall (center of the distant wall in my photo) leaked roof spillage into the space beneath a basement floor that had been installed on sleepers (2x6 lumber glued to the floor slab).

Wet basement repair (C) Daniel FriedmanNo one noticed that water was beneath the floor until more severe weather conditions combined with snow and ice outdoors put so much water below the floor that it appeared up through the subfloor and onto the carpet-over-plywood that had been installed in this finished basement.

The prolonged presence of water in the sub-floor space led to a flooded basement complaint requiring demolition and cleaning.

To minimize the chances of a costly mold contamination problem (that would have required more extensive demolition) the owners cut up and threw outside the soaking wall-to-wall carpeting and removed other wet items from the basement immediately on discovery of the water problem.

Using a shop vac water was removed, then the subfloor was also removed to give access to the space below.

Questions arose including: should we paint a sealant on the concrete floor surface before restoring the new floor? Is there a problematic mold reservoir on the under-side of the wood sleepers and does that need to be addressed?

We pulled up a few sample sleepers in the floor area that had suffered most protracted leakage (these were the most-stained boards) and saw no mold on the underside (glue had sealed the wood surfaces). When the floor was cleaned, dried there were no odor complaints and there was no visible mold.

We also made use of some air and surface tests. No sealant was applied to the concrete. A new floor was installed.

Concrete dust odor complaints: sources, causes, mitigation

Concrete being placed at a Vassar College construction site, Poughkeepsie NY 2013 (C) Daniel FriedmanCommon Sources of Concrete Dust in Air & Building Dust

Common Sources of "Concrete Odors" found Indoors [Opinion]

 

Reader question: I visited a school in Boston today. In some parts of the building there was an irritating smell that seemed like cement dust. I was told the smell has been there for at least a year. I had been to the building a few times about three years ago and I noticed no smell then.

Photo at left: fresh concrete being placed at a New York construction project. There may be a "wet concrete smell" associated with new pours but that is not genrally associated with IAQ or odor complaints - Ed.

The smell was exactly like what I remembered coming from a limestone rock I got in central Florida when I washed it. Tonight I smelled the rock when it was dry and put my nose right up to it and no smell. Then I got it wet and it had that same very strong irritating dust smell as the school. So at least with with my limestone rock it is washing and getting it wet that causes it. So it is not like dust you can wash away.

I think a woman at the school said they had done a lot of cleaning. Maybe getting cement/concrete wet? I remember this smell, but never as strong, from when I was a kid. Public schools or maybe my father's university office building built probably in the late 1960s earl 70s with exposed concrete.

The smell at the school really bothered me and one of the staff members was herself bothered by it enough to open a window. I am pretty sure it is not good for you especially if you have asthma. Any ideas you have on this will really be appreciated. - K.H. 9/17/2013

The smell seems so much like dust even though it is couterintuitive that it is caused by wetting my limestone rock. So maybe it actually is dust that is somehow chased out of the rock by wetting. Maybe the folks at the school keep mopping to clean it but that creates it. I remember at the school today the smell made me remember the that dusty smell from right after a school janitor would mop the hall when I was a kid. - K.H. 9/17/2013

Reply:

Old broken up concrete walk - not likely to be a source of concrete odors but a dust source during demolition (C) Daniel Friedman Take a look at SMELL PATCH TEST to FIND ODOR SOURCE and think about doing a couple of simple tests using that procedure. Kenneth, I've thought about this further and have the same impression as you.

For example, I frequently observe an odor that some people describe as "concrete smell"  in a city in Mexico (San Miguel de Allende) in an area of heavily-trafficked concrete and cobblestone paved streets at the start of a rainstorm after a dry period.

The initial rainfall actually increases the level of airborne dust - a subject that I am studying.

AIR QUALITY STUDY San Miguel de Allende (just in its infancy, I need more samples).

My smell patch suggestion earlier was intended to make sure that the reported odor is not traced to something that spilled on the concrete, and that the odor actually is emitted from that source - most likely when wet as you suggest.

Please keep me posted on how things progress, and send along photos of the area you are discussing, or additional details if they occur to you, such as the relationship between the odor detection and time of day, weather, building cleaning operations, operation of HVAC systems etc. Such added details can help us understand what's happening and often permit some useful further comment. What we both learn may help me help someone else.

What are the Harmful Constituents in Concrete Dust

Concrete Dust & Odor References on Concrete Expozure Hazards & Silicosis

Some useful references about concrete are below. Some of these address the hazards of concrete dust or its control, others, odor sources.

 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2020-06-29 - by (mod) - clean concrete and seal it; don't expect to get all odors out before sealing

In my limited experience, especially porous, non-polished concrete, absorbs liquids and odors such that it can be almost impossible to clean enough to get the odor level back to zero.

That's why I've combined cleaning, rinsing (not just to remove dirt but to remove chemicals that might interfere with bonding of the sealant), then using a sealant, such as a low VOC sealant rated for use on clean concrete. .

Most AZ construction is on slab; keep in mind that the wall sills and lower walls can have been wet with anything that flooded the building, so lower wall cleaning and sealing of the wall cavity may be in order.

On 2020-06-29 by Anonymous

thank you. This will be my second attempt to wash the concrete, the first attempt did not eliminate the odor however i did not vacuum up the water, so the dirty water redried which probably made my attempt rather useless.

I bought a dustless wet / dry vacuum. I will vacuum up all the baking soda on the floor. Then mix water with Borax in a bucket and use a firm push broom to scrub the floor.

I will then rinse with a light pressure hose and have a second set of hands vacuum up the water since its interior as its being rinsed. I will have to do it in sections to avoid a complete flood. I live in AZ and its about 110 out right now.

The window will be open and i will have a large industrial fan in the room and i will let it dry for a week. I will remove the baseboard, since that will be replaced anyhow later on. Hopefully it works. Thanks again for your help.

On 2020-06-29 - by (mod) - Non-TSP non-detergent cleaners that might help clean smelly concrete surfaces

Borax is a good substitute for the now outlawed TSP non-sudsing detergent type cleaners.

Other products include

Krud-Kutter
TSP-PF TSP Phosphate Free
Savogran
Simple Green
KleanStrip

Just what's needed to lean a concrete surface depends on its location and condition and level of dirt. I have used a long handled scrubbing brush, a push broom, cleaners, and lots of rinsewater in cases where getting rid of the water wasn't an issue (like mopping to a doorway or to a sump)

It's important to rinse the surface of all cleanser
And
It's very important to allow plenty of drying time and to be sure that all of the floor, including at edges and corners and penetrations, is dry (at least below 18%) before using a sealant

Then the sealants we described below can work well.

On 2020-06-29 by Anonymous

based on your article it says to clean concrete floors use a non-sudsing detergent. Can you clarify? Apparently these are very hard to find. The only thing i can find is Borax. Also did you use a brush or what was used to clean the concrete? Thank you

On 2020-06-28 by Anonymous

ok thank you i will give those I try i need to make sure they are also non toxic and VOC free. After this exposure, i am chemically sensitive.

On 2020-06-25 - by (mod) -

Will

Thanks for the discussion.

No, there are some sealants that specifically claim they're fine for use beneath tile.

Take a look at FLOORING ADHESIVE MASTIC SEALANTS

and give a couple of those companies a call to see if they agree that their product will work for you.

Be sure the floor is dry.

On 2020-06-25 by Will OConnell


yes i read that and the article is very helpful. What i realized is i did wash the floor but the dirty water was soaked back in and using a wet vacuum might be my missing step. Yes i am certain the odor source is the vapors the concrete absorbed from the 3 years the foam underlay was on the concrete.

If i seal it though, doesnt that make putting tile on top of it a NO go? Doesnt the tile need porous concrete to adhere to?

On 2020-06-24 2 - by (mod) - odor of exhaust fumes vs other odor sources

Will

If you need to be certain in the ARTICLE INDEX you will find our description of an easy do-it-yourself

SMELL PATCH TEST to FIND ODOR SOURCE

Or if you are already certain that the odor source is the concrete floor and you have cleaned it as best you can then when the floor is dry you may need to seal the surface with a low VOC sealant

On 2020-06-24 by Will OConnell

Hi, I recently started having some serious allergy / asthmatic symptoms in my house and noticed I was smelling fumes in my office. It smelled like exhaust fumes.

After about 6 months of hitting dead ends I became frustrated and angry and ripped out my carpet and carpet padding in my office.

I was expecting to see mold on the carpet, however what I smelled was some serious chemical vapors coming from the foam carpet underlay.

I immediately removed it all along withe tack strips and cleaned up the concrete floor. I then washed the floor with dish soap and water. Once it dried I put baking soda all over the exposed concrete foundation and swept it up 2 days later. I left the room air out for 30 days sealed off to the rest of my house with the window open and an exhaust fan drawing the air out. Unfortunately that chemical odor still remains in my concrete.

Any idea how to remove that odor or what to do? I wanted to retile my office with porcelain tile but not sure if it will seal the odor and I believe the odor was making me sick. I reached out to the manufactorer and recieved their safety data sheet and it has TDI's in the foam underlay which is what i suspect is causing the odor. Its important for me to not only neutralize the smell but to make sure the vapors are gone for health reasons.

I unfortunately have this carpet in 4 more rooms in my house and I cannot remove it even though it is making me ill because the vapors after removal are worse then whats seeping through the carpet. The manufacturer is avoiding me. I have no idea how to handle this. Here is what is in the foam:

Polyurethane foam is a reaction product of toluene diisocyanate and/or methylene bisphenyl isocyanate, water, and polyols (may be polyoxyalkylene polyether polyol or polyester polyol, or bio-polyol derived from renewable resources, or a combination of these polyols). May contain trace amounts of insoluble processing aids, pigments, or reactive dyes.

Any help of who to contact or how to neutralize the odor would be appreciated.

On 2020-05-10 - by (mod) - Cats have been urinating on the concrete porch

Christine

I think your poison control people were on Target and that you need to wash off that pot pourri of chemicals that you've been pouring around your house.

First of all that mix complicates things since we don't know which smell is doing what,

and secondly some combinations of chemicals such as bleach and ammonia can be very dangerous. So never use those two together.

A combination of cleaning with water or other very mild cleaners can reduce the level of chemicals on surfaces around your house but it may take some time and lots of fresh air for the orders to dissipate if they have soaked into the concrete or into other building materials.

It is the case that once cats have peed in a particular spot they will go back there out of recognition of a familiar scent. I hesitate to suggest pouring more things around the house until the current odor and air quality issues have been resolved.

I have on occasion and able to stop a neighborhood cat from peeing and pooping around a particular place by cleaning the pee and poop spot and then leaving a small amount of ammonia on the ground in that exact area.

The naughty that I follow closely very much dislike ammonia.

On 2020-05-10 by Christine Harrigan

Cats have been urinating on the concrete porch. Over the past 2 months, we have used Mister Max's P-Bath and Enzymes, bleach, hydrogen peroxide, Dawn, 100% white vinegar mixed with baking soda, and Nature Sunshine Enzymes.

About 2 weeks ago, I used Mr. Maxes Enzyme solution on 2 areas on the front porch where I could smell urine. Within an hour, I was out the house. Hot fumes and gases came into the house for about a week.

When it was better, I returned inside the house. Sadly, birds were seen pooping and urinating above the door frame of the front door. We cleaned the area with vinegar and water. One night I was watching TV and a terrible chemical order came into house and I experienced nausea.

I went to the spot where it was entering, which was the the concrete area near the front door below the door frame. I placed baking soda over the area and a foul oder resulted.

Within an hour, I poured 100% white vinegar and baking soda. It was better. By morning, I could not smell an odor. I boiled water and poured it over the spot 5 times. I waited 2 days and then used Nature Sunshine's Enzymes on that area, covered by a tarp for 24 hours. I removed the tarp and an explosion of hot fumes and gasses flooded the house.

I have burning pain in my respiratory system when I fo near the spot, outside or inside the house. Poison Control told us to rinse the area with water, which we did. This was the same chemical smell I experienced earlier. What has happened and how do I fix this?

On 2019-12-12 - by (mod) -

I believe you for sure, April, but what you were smelling was not likely to be ceramic dust from the manufacturer; too little and too inert.

You would not be likely to be able smell asbestos itself - it's a mineral dust or fibre.

But smells emanating from electric and other heaters are common as dust, deposits of any other sort as well, are heated-up.

On 2019-12-11 by April

Thankyou - I smelled it very strongly

On 2019-12-11 - by (mod) - leftover from manufacturing, asbestos dust on ceramic heater elements?

April anything is possible, I have not a shred of evidence about manufacturing dust on ceramic heater elements, but in any event, in my OPINION there is not a shred of a chance that residual dust from manufacturing of the ceramic supports and components in a floor heater would be a significant or even detectable contributor to indoor air quality issues in a building.

The potential volume is just too small to be meaningful.

On 2019-12-11 by April

Do you think that when the ceramic elements were manufactured that there could have been ceramic dust on the elements from the manufacturing; and then the elements were put into the heater with the dust still on them ?

Noisy ceramic heater may be shedding ceramic dust from loose fan - odors? (C) InspectApedia.com AprilOn 2019-12-04 by (mod) - is this noisy ceramic heater shedding dangerous silica or ceramic dust?

April:

A handy person might dis-assemble a portable electgric heater to find and tighten a loose screw or set-screw or similar part that is making a fan rattle or tick or hit other internal heater parts.

Watch out: however I warn that the heater may already be damaged and unsafe - risking an electrical fire, or you may make it unsafe by operating on it.

It might be smarter to return the unit for credit and buy something else. The concern is for electrical safety, not silica dust.

I add that a Google Scholar search for research on "Silica Hazards of Electric Heaters" produced no findings.

On 2019-12-04 by April - is this noisy Comfort Zone Brand ceramic heater shedding dangerous asbestos or ceramic dust?

To inspect this I would have to take the heater apart ? The fan does rattle and tap

I did get the heater through freight shipping

On 2019-12-04 by (mod) -

Very good question. I would expect that you would both see and hear the fan was hitting something. The distance isn't the whole question as a fan can become loose. But I would think you would hear the rattling or tapping and on inspection you would see the point of impact.

On 2019-12-03 by April

Do you know if the fan on the heater is far away from the ceramic elements ? Could the fan blade be hitting the element grinding it ?

Do you think the shipping could have been rough on the heater causing any of the things that you mentioned?

On 2019-12-02 by (mod) -

April:

Ceramic backers in electric heaters like the one in your photo are not normally friable and wouldn't shed particles unless something quite abnormal were going on such as mechanical disturbance that's grinding or sawing the material or causing it to shed.

On 2019-12-02 by wheelo160162

April

On 2019-12-02 by April

I did get the heater through freight shipping

I have added a picture [shown above in this section] along with other comments.

The fan makes a weird noise too as though it’s hitting something or as though its off it’s proper track

The fan makes a weird noise too

On 2019-12-02 by (mod) - ceramic heater with PTC ceramic elements and a fan.

April

With the apology that I cannot see nor know enough about your heater and home to diagnose your complaint, it would be quite odd for a heater, even with a cementioius backboard, to be spewing sufficient cement or ceramic dust into a home to be detectable.

It is, however, common that a brand new heater, first turned on, may emit a bit of odor as it burns off dust or thin deposits of lubricants or sealants; Such odors may recur too if a heater was stored where it accumulated dust or debris.

A photo of your heater in operation would be helpful. Use the " add image " button.

On 2019-12-02 by April

I have a ceramic heater with PTC ceramic elements and a fan. When I ran the heater there was a strong smell of cement dust - I felt large particles in my eyes. I later smelled a strong cement dust smell from my urine.

Ceramic has silica in it. Do you think that an element broke and the fan spread the ceramic dust around? Do you think that the factory that made the elements left ceramic dust on the elements which then went into the heater - ?

On 2018-05-07 by (mod) -

Theresa,

Well it's possible that the cleaning job created a residual dust problem, I would first one to know whether there is a residue from a cleaning agent that is off-gassing and bothering you. Check with a cleaning company, identify the cleaner that they used, and let me know what that is and I will help you find the material safety data sheet for it.

On 2018-05-06 by Theresa shaw

Powerwashing concrete was done at home l rent the smell was very strong since cleaning having hard time breathin l have copd and emphzime could the cleanin cause a lung problem for me

On 2017-07-22 by (mod) -

Try cleaning the area thoroughly with a detergent then rinse it thoroughly then let it dry thoroughly. If the odor remains you might need to use a concrete floor sealant.

You might also try as a cleaner using products intended to remove pet urine or pet stains from floors before giving up. You can also search inspectapedia using the search box just above for URINE ODOR REMOVAL to find our article discussing this problem and cleaning approaches

On 2017-07-21 by Anonymous

Remove urine from concrete


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