Questions & Answers on using a smell patch test procedure to help track down odor sources in buildings.

This article series describes a simple procedure using paper towels and aluminum foil wrap to track down odors in buildings, such as but not limited to tracking down mold smells, sewer smells, plastic smells, chemical odors, animal odors, and even new smells that occur after excessive indoor use of ozone in buildings to try to "kill" mold or remove other indoor odors (skunks or smoke).

Our page top photo shows the last step in the smell-source test procedure, though we recommend that this step be conducted outdoors in fresh air.

FAQs on How to Find the Source of an Indoor Smell

These questions and answers about using a low-cost and easy procedure to track down odor sources indoors were posted originally

at SMELL PATCH TEST to FIND ODOR SOURCE - you will find that article worth a look.

On 2022-12-04 - by (mod): who can I call for an odor diagnosis on-site

You might try calling local environmental test consultants and home inspectors, but before hiring someone, ask about their experience, and ask what they'll do in your home and what sort of report you can expect.

If the expert is interested in what you've already done, if she will perform a thorough visual inspection and take a history of the building and of your odor concerns and also note any particular vulnerabilities of building occupants (pregnancy, a new baby, or elderly, asthmatic or odor sensitive people, for example) then that's encouraging.

As we've discussed before, I would not hire someone who's going to just stop by to "do some air tests" that will be sent to a lab who will then toss their report over the wall back to you.

To do some investigative work yourself do take a look at our

ODOR DIAGNOSIS CHECKLIST, PROCEDURE

On 2022-12-04 - by Chris: not confident that the floor is the culprit: sweet chemical smell

[1] Water stains below the subfloor and under the roof

> If you're confident that the smell comes from the floor but cannot characterize it we face a greater challenge: are we looking for a dead animal, mouse infestation fecals and urine, previously-used pesticides, spills of unknown substances, paints & coatings, or odors from a neighbor's abutting unit (below, above, aside), or something else.

So give that some thought if you can.

Unfortunately, I'm not confident at all that the floor is the culprit. What I can tell you is that this is the only room that smells - the neighboring hallway, bathroom, living room and kitchen (or the other bedroom) don't have it.

I can't really characterize the smell clearly, it has a bit of a "sweet" or "chemical" note to it, but I'm not trained to put it on a map (fun anecdote, I was hoping the inspector we hired would help with this, but his aftershave outdid the smell ;)).

I will say that there are traces of previous water damage [photo below] in the wood (both under the ceiling, so it could have been running down along some beams) and the subfloor from below.

That said, we're in Southern California and given the little rain we get it's hard to imagine that this would have had such long lasting consequences. FWIW, I checked everything with a moisture meter and couldn't find any active leaks.

Also, the neighbors below smoke in their unit, but as far as I know they smoke everywhere (not just in the room below).

Another thing to note is that they keep cats in the room below, but when they let me peek into the room below ours to check for moisture (didn't find any using a moisture meter), I didn't smell anything noteworthy besides cold smoke (which, granted, could have covered other smells).

There is a current in the building, presumably coming from below (I can feel it when getting close to things like electrical outlets or light switches, I even did a smoke test).

> We found the problem by cutting an inspection strip across the entire width of the ceiling, about 12" wide, to permit inspection of the whole ceiling, all cavities.

It's much easier and cheaper to cut and repair drywall than to ruin an installed hardwood floor. (I hope your test cut was in an unobtrusive location).

That's an interesting approach.

Question for you: What type of inspector would you recommend for this sort of thing?

Or if I do this myself, what would be a checklist of things to look out for (water stains, mold growth, something else?)?

> If you think the odor is from a finish ON the hardwood floor it could be stripped, sanded, and re-finished. [Actually we're doubtful that this is the odor problem - Ed.]

To be honest, I don't think it's from the finish because the same finish was used in the entire unit (and as noted above, other rooms are fine).

> How much time do we have left of the 6 months of gestation (or adoption?) ?

Our daughter is coming mid April next year, so we still have some time to figure this out (worst case, stripping the whole room, drywall and flooring).

> Worst case: you can install an air-to-air heat exchanger fresh air ventilation system https://inspectapedia.com/BestPractices/Balanced_Ventilation_Systems.php

Thanks for that idea. I was actually planning to apply some positive pressure using a ventilation fan to see if that helps (I had previously tried to vent just from underneath the closet because I suspected that to be the origin - which it turned out not to be, see [Photo 2- below]).

[2] Deconstructed & reconstructed our closet

...

On 2022-12-04 - by (mod) Quick Review of Results of test cuts into flooring - odor source tracking

If you're confident that the smell comes from the floor but cannot characterize it we face a greater challenge: are we looking for a dead animal, mouse infestation fecals and urine, previously-used pesticides, spills of unknown substances, paints & coatings, or odors from a neighbor's abutting unit (below, above, aside), or something else.

So give that some thought if you can.

Inspecting with a borescope is useful but very limited. You're only seeing a very limited area of the floor structure. I've inspected a building that later had to be partly-gutted, following up a ceiling mold odor. We found that a prior flood had sent water through two (out of about 20) ceiling cavities formed by the floor above and ceiling below and floor joists along the sides. Water ran down at a specific point, through two ceiling joist bays, across the room, and down an opposing wall. you would never find this with a single borescope check.

We found the problem by cutting an inspection strip across the entire width of the ceiling, about 12" wide, to permit inspection of the whole ceiling, all cavities. It's much easier and cheaper to cut and repair drywall than to ruin an installed hardwood floor. (I hope your test cut was in an unobtrusive location).

If we had an idea of the nature of the odor we might have some clues about where and how to look. Sealing off a whole floor with foil was a clever idea. Even if some odor leaks around the floor perimeter it ought to be substantially reduced.

If you think the odor is from a finish ON the hardwood floor it could be stripped, sanded, and re-finished. But I would avoid doing anything dramatic and expensive before we've a better idea of what we are looking-for (to dangle a preposition).

How much time do we have left of the 6 months of gestation (or adoption?) ? I certainly don't want to risk subjecting a newborn or anyone else who may be vulnerable to an unknown contaminant - the worry itself, alone, is bad for your health.

Worst case: you can install an air-to-air heat exchanger fresh air ventilation system

VENTILATION, BALANCED

I'm including my editor Amy on this note in case she has a suggestion to go along with her acute sense of smell.

On 2022-12-04 - by Chris: Results of test cuts into flooring - odor source tracking

I fully agree with you [about the limits of testing the air in buildings to diagnose odors]; that said, I'm having a hard time to find the right local inspector :(.
Now, in the meantime I followed (a variation) of your advice and did the following:

...

1) Drilled a hole in the hardwood to see if there is mold or anything like that in the rosin paper or in the layers of the hardwood ==> at least the area I checked seems to be clear (noting that I might be looking in the wrong place), see

2) Checked with an endoscope camera for mold or dead rates through the newly drilled hole ==>

there's a layer of dust or debris of some sort on the neighbors ceiling below, but no obvious signs of mold or other suspects (noting that I might be looking in the wrong place).

3) Tried to tape off the entire floor with a foil (I used one that is usually used as underlayment / moisture barrier). The thinking was that maybe we can just put vinyl flooring on top of the hardwood to isolate the smell (similar to your suggestion of trying to coat the wood). The result is mixed... the room still smells, although I seem to perceive it as less intense (although my wife doesn't see a difference).

Question for you: Do you think there's a point to this "experiment" or should we expect the smell potentially originating from the subfloor find another way anyway? Is this material a suitable odor barrier? If not, is there a better one?

Finally, when rearranging our furniture for laying out the underlayment, I found the following dark spot in a corner below a bookshelf.

Do you think this is a smoking gun for pet stains?

Reminder - as you'll see in our earlier conversation below, we already tried your "smell patch test" on several areas of flooring. We did that after coming across your website (back in Feb 2020). Unfortunately, we couldn't conclusively narrow down the area (I think part of the reason was that the painter's tape has a strong smell which makes it hard to identify the more nuanced smell). 

Unfortunately, we couldn't conclusively narrow down the area (I think part of the reason was that the painter's tape has a strong smell which makes it hard to identify the more nuanced smell). 

On 2022-11-16 - by (mod): limits of air tests for "odors" in buildings

The problem I have with the testing approach is that even if it suggests there's a problem you don't know what to do about it. It's a better use of your time and money to actually do the physical exploration and inspection. At least that's my view.

On 2022-11-16 - by Chris: progress on tracking down odor suspected coming from finished hardwood floor

It's also the case that far more reliable, safer guidance will come from having an on-site expert  discuss your concerns, take a thorough case and building history, inspect the building exterior, interior, mechanical systems thoroughly if that's required, perhaps provide a bit of ancillary testing (never rely on tests alone), provide findings in writing, and answer your follow-up questions.

I actually called around trying to find a "detective inspector" to help us narrow down the source of the smell. I finally arrived at a highly recommended professional mold inspector. I explained our situation and exactly what we want to get out of it (finding the source of the odor as opposed to running a few standard checks).

He came by, ran an air sample mold test as well as cavity samples, which all came back negative. He also looked for active leaks (humidity sensor) and actually flagged something close to the closet. However, it was a humid day, so I bought a sensor myself and checked the following days with no trace of any moisture.

So in summary, the professional inspector I could find so far seemed to apply their standard tests, but didn't really dig into the problem with a detective mindset. This experience was slightly disheartening. That said, please let me know if you have any advice on what exact text to look for, for example on Yelp ("building inspector", "industrial hygienist", something else?).

I would be very reluctant, too, to tear out a hardwood floor. I'd have to be certain that there was a significant mold or other odor source on the subfloor between the finish flooring and the subfloor, and even then I might try sealing both sides of the floor - refinishing the upper surface and using a sealant paint on the under-surface

I will definitely try this (at least the upper surface since the lower surface would need to be accessed from my neighbors' unit), thanks! Even if it gets better (but isn't quite fixed), it helps narrow down the source. Relatedly, I was also considering rolling out an odor barrier foil (please let me know if you have a

SO I suggest making a test cut in an unobtrusive but most-suspect area of the flooring - perhaps from below: you don't need to cut through the upper surface of the finish hardwood floor. 

Yes, I'm considering this too (although it's not obvious to me where the best spot is).

> Watch out: in general it's risky to ever leave a mold reservoir in a building: MVOCs or an inoculation promoting new mold growth if new leaks or high moisture are present are reasons that we remove such materials.

I was considering ordering a VOC test, but I'm not sure if these explicitly detect MVOCs (or other potential VOCs, e.g. originating from pet urine). Again, please let me know if you can recommend a lab / way to self-test for those things specifically.

Thanks again for your kind help, I'll keep you posted.

On 2022-11-15 - by (mod) - confirm the odor source - between finish flooring and subfloor? What then?

I must send my regrets that our workload as well as the urgency of your situation preclude telephone, in-person, and any lengthy email consulting, whether pro-bono or paid, concerning the question(s) that you have raised.  

About your odor concern, I would be very reluctant, too, to tear out a hardwood floor. I'd have to be certain that there was a significant mold or other odor source on the subfloor between the finish flooring and the subfloor, and even then I might try sealing both sides of the floor - refinishing the upper surface and using a sealant paint on the under-surface

(we discuss those

at ASBESTOS ENCAPSULANTS & SEALERS 

I don't think a lot of odor off-gassing occurs up through wood flooring, so if the upper floor surface is coated with clear semi-gloss poly or a similar product and if there are no open flooring gaps you might find that is sufficient. 

Watch out: in general it's risky to ever leave a mold reservoir in a building: MVOCs or an inoculation promoting new mold growth if new leaks or high moisture are present are reasons that we remove such materials.

SO I suggest making a test cut in an unobtrusive but most-suspect area of the flooring - perhaps from below: you don't need to cut through the upper surface of the finish hardwood floor. 

Be sure to read

HIDDEN MOLD in FLOOR / SUB-FLOORING 

and

TRAPPED MOLD BETWEEN WOOD SURFACES for a discussion of the immobility of mold between wood framing and other surfaces.

It's also the case that far more reliable, safer guidance will come from having an on-site expert  discuss your concerns, take a thorough case and building history, inspect the building exterior, interior, mechanical systems thoroughly if that's required, perhaps provide a bit of ancillary testing (never rely on tests alone), provide findings in writing, and answer your follow-up questions.

In five decades of building, environmental,  and forensic work it has been my experience that at every case in which I was able to actually visit and inspect a property there were critical observations and conditions that simply were not obvious to a normal home owner, buyer, realtor. It's not that the inspector is necessarily smarter,  but rather that they have different experience. 

E-text, reports, photos, phone calls are never a substitute for an on-site expert.

CONSULTANTS & EXPERTS DIRECTORIES   may be of some help to you.

On 2022-11-15 - by Chris - what to do now about smell from hardwood floor

... we had been in touch in 2020 through comments on your website (https://inspectapedia.com/odor_diagnosis/Smell-Patch-Test-Kit-FAQs.php).

After taking a break over the pandemic, we're expecting a kid in half a year and will need the space, hence I'm now back trying to resolve this issue with urgency.

The best next thing I can think of would be ripping out the floor and subfloor, but as you can imagine this would be very expensive (and the thought of ripping out those beautiful 1948 wooden floors pains me!)

Hence, I wanted to ask if you'd be willing to consult on this issue from a distance over phone (at some hourly rate or whatever you have in mind) and/or video chat? It'd be a great help as I think I need someone with a "detective mindset" to systematically guide me through this.

Please let me know your thoughts! - Anonymous by private email

On 2020-03-09 - by (mod) - expert for tracking down the smell source first to a surface or indoor or outdoor material

I don't have a specific expert whom I can recommend. What's important is to talk to the prospective investigator to find out their experience and their approach to the concerns that you have.

On 2020-03-09 by Chris

Thanks for all your help Dan. Again, I'll try to confirm that this area is the source and proceed with cleaning, refinishing or removing the floor.

Please let me know if you can recommend any professional for this kind of ticky diagnosis job in the Los Angeles area (I've already started looking at the Expert Directory, but wasn't 100% sure who would be best for this particular situation).

On 2020-03-08 - by (mod) - water stains on subfloor are an indicator in tracking down the smell source

That is certainly a water stain; that also means there may be mold or ? between the upper surface of the plywood subfloor and the under-side of the wood flooring; also if there was rosin paper between flooring and subfloor it could have hosted mold or something else.

A blacklight on those stains might suggest (if efflorescing) urine.

(See our PET URINE articles in the ARTICLE INDEX ).

On 2020-03-08 by Chris - overcoming odor of tape when using the smell patch test kit

Yes, exactly. I'll try the bigger margin, that's a good idea.

In the meantime, I managed to drill a hold to get below our floor and get a picture from the bottom of our floor using an endoscope camera (see picture here: https://ibb.co/44NXNdD).

It sure looks like there are stains, so it's safe to say there must have been urine or water at some point in the past (bleach stains on top, water marks below and a squeaky board). I didn't see any mold though. Now what is unclear to me is whether something like that can cause a noticeable odor in an entire room even years later.

Before taking any dramatic action, I'll double check (maybe with more patches) that it's indeed localized to this area (and in particular not coming from the downstairs' neighbors place).

On 2020-03-08 - by (mod) -

Thanks for the painter's tape warning.

Am I right that the problem of odor from the tape is notable because as you quickly fold the test paper towel into the center of the foil the tape's odor is adding itself to your paper towel? If so, perhaps use a larger margin of foil around the paper towel.

On 2020-03-08 by Chris - painter's tape contaminates odor source test

Thanks Dan. As for condensation, I see it's happening in the downstairs neighbors windows as they only have single-pane. Our windows are new double pane windows, so no condensation there (maybe in the wall).

In the meantime, I've done 4 more patch tests (hopefully) confirming that it's not coming from the wall (at least not the wall's surface) and it seems to be localized to one side of the room.

One thing that turned out to be particularly difficult in the patch test was the strong smell of the painter's tape itself (blue Scotch tape), which can make it hard to tell with certainty if there's another smell in the patch. I'll experiment with other tape going forward.

In the meantime, I've removed one of the baseboards (see attached picture) to investigate if I can see any traces of mold or water damage (no luck). I feel like the smell has gotten much worse since removing the board, which could indicate that we're on the right track.

As for next steps, I might drill a hole where the floor is otherwise covered by the baseboard and get an endoscope camera in there to inspect the space below.

If that doesn't help, I might try to remove one of the boards in a non-destructive way, so I can put it back later.

On 2020-03-04 by (mod) - offgassing sources in buildings

Chris

No I was looking at the possibility of vinyl offgassing - occurring more notably on the warmer sun-exposed side.

But yes on a shaded or cooler side there might be condensation; You could try a visual inspection for leak history as well as a thermal scan.

On 2020-03-03 by Chris

Dan, a couple more patch tests are in progress, will report back on what I find!

As for your questions.

> Also let's consider an exterior source: what's the siding on the building?

That side of the building faces the common garage area. There is a small patch of soil right next to the building and the garages are about 6 yards away.

> Are there plastic or vinyl windows, screens, or siding?

Yes, there are indeed plastic (vinyl?) windows and screens in the room. However, we have the same type of window in the other bedroom that lies on the same side of the building.

> Differences in sun exposure for this exterior wall?

This is actually something I'm particularly worried about. This wall lies on the north side of the building and gets very little sun exposure in general (actually none this time of the year - March). Are you thinking there might be condensation -> mold?

On 2020-03-02 by (mod) - tracking down the smell source first to a surface or indoor or outdoor material

let's at least be sure it's the floor not walls or ceiling;

Also let's consider an exterior source: what's the siding on the building?

Are there plastic or vinyl windows, screens, or siding?

Differences in sun exposure for this exterior wall?

This Q&A were posted originially at ODORS GASES SMELLS, DIAGNOSIS & CURE

On 2020-03-02 vby Anonymous

Dan, thank you for your prompt response. I left some responses inline below.

> Urine, perfume, smoke, mold - are four very different odors. If we could form a more-confident opinion that might be diagnostic.

You're right of course, but it's very hard for me to tell them apart as I don't have a good reference. For what it's worth, we've first noticed the smell over a two years ago and it hasn't disappeared by itself since (potentially ruling out some causes like a dead animal).

Do you have any suggestions on how to narrow down the nature of the smell (maybe some kind of flow chart, device or lab test that may exist)? It's really hard to describe the smell in words.

> If the smell were from a spill it wouldn't be likely to be uniform all over the floor.

That's a good point. I feel it's more noticeable in particular corners of the room, but this might be something to confirm with additional patch tests.

> Pet urine usually leaves a stain and perfume might also affect floor finish and be visible.

Yes, I don't see any big stains (other than the small dark discoloration next to the bleach stain in my picture). We did, however, refinish the floor after we purchased the unit two years ago (also in the other rooms that don't smell).

> Before cutting up the floor to look into it you might think about a less destructive inspection from below

Going from below is a good idea too (something I'll need to discuss with my downstairs neighbor).

> In the worst case I might try cleaning and re-sealing the entire floor surface with a low VOC sealant;

Do you happen to have a recommendation for low VOC sealant?

> Or do some smell patch tests on the walls and ceiling and on furnishings.
Yes, more patch tests seem in order to validate the hypothesis that it's actually coming from the floor.

> For that matter, as you'd need to empty the room to do anything to walls, ceiling, floor anyway, have you considered emptying the room, airing it out and seeing what happens to the odor?

We've first noticed the smell before we had any furniture in there. I've also tried clearing out any textiles a while ago (bed, towels and such in the closet), but it didn't help.

Thank you again for taking the time to give advice, it's really much appreciated!

On 2020-03-02 by (mod) - trouble isolating smell source in LA home

Chris

I would be slow to replace that flooring - I'll attach your photo below for other readers to see;

Urine, perfume, smoke, mold - are four very different odors. If we could form a more-confident opinion that might be diagnostic.

It might be useful to decide if the probable cure of this odor complaint is going to be solved by spot treatment or if we need to clean or re-finish the whole floor.

If the smell were from a spill it wouldn't be likely to be uniform all over the floor.

Pet urine usually leaves a stain and perfume might also affect floor finish and be visible.

Before cutting up the floor to look into it you might think about a less destructive inspection from below: go to the most-suspect spot, then if the ceiling below this floor is drywall or ceiling tile you can cut an inspection opening to look for hidden clues about what's going on: mold, stains, dead animal, etc.

We'd like to decide that the smell isn't from a source that can be removed (animal, insulation, moldy material)

In the worst case I might try cleaning and re-sealing the entire floor surface with a low VOC sealant;

Or do some smell patch tests on the walls and ceiling and on furnishings. For that matter, as you'd need to empty the room to do anything to walls, ceiling, floor anyway, have you considered emptying the room, airing it out and seeing what happens to the odor?

On 2020-03-02 by Chris

Dan, first of all, thank you for the wealth of information on this site, I've used a lot of it in trying to triage a smell in one of our bedrooms.

We live in a condo in Los Angeles, second floor, built 1948. The smell can be characterized as almost a bit sweet and stuffy. It's not strong when the doors and/or windows are open but is clearly noticeable after a few hours if the room is closed.

Our first thought was that it may be coming from the closet because the bathroom is right behind it and has pipes running down. We replaced all closet walls, but the smell returned.

In desperation, I started sniffing around the room and it appears that the hardwood floor seems to have a smell in certain areas that resembles the smell of the room

. I was able to confirm the smell on the hardwood using the "quick test" you suggested:
https://ibb.co/HxZwTSV

I think it could be one of:

* Pet urine from the previous owners (there are some spots of bleach indicating that someone tried to clean up before)

* Old perfume (the previous owners had a dresser with various lotions and perfumes in this particular room)

* Smell coming from the downstairs neighbor's unit (maybe smoke?)

* Mold below the hardwood or in the subfloor

* The smell coming from somewhere else in the room (maybe old plaster wall?) and the wood just absorbing the smell

I already tried to clean a path of hardwood with vinegar and cleaning agent, but it doesn't seem the wood smells noticeably less around that spot.

As a next step, I was planning to talk to the neighbors again to see if there is anything special about this particular room (the other bedroom that's above their other bedroom doesn't smell). Before they claimed there is nothing special, so I have little hope to find anything there.

After that, I might bite the bullet and drill a hole into the hardwood to see if there is mold or something else underneath. Next, I would try to refinish the hardwood and finally (if everything else fails) replace hardwood, subfloor and plaster walls.

Please let me know if you have advice or suggestion which additional things we could check or what to do before taking any of the above dramatic measures.

Best,
Chris

On 2020-03-10 - by (mod) - using FireBLock foam to seal hole in a floor where electrical conduit enters a building

Frog

I would consider a fire-rated or "FireBlock" Gfoam spray sealant - thus not encasing wires in concrete and causing a lot of trouble for someone in the future. An example is shown below. Check with your local electrical inspector.

On 2020-03-10 by Frog

I have converted a stone barn built in 1848 into a house. For hundreds of years the barn housed cows and other animals. In a utility closet there is a hole in the concrete floor where all electrical conduits and pipes enter the building. There is odor coming from the hole.

I believe the odor relates to the animals having lived there for so many years. I no longer need access and would like to fill in the hole to block the odor. However, because of all the conduits and pipes, the fill needs to be a liquid solution such a wet concrete. Is concrete a odor blocking solution?

On 2018-12-02 by (mod) - vinyl and other plastic products can be a source of off-gassing and odors

Indeed some vinyl and other plastic products can be a source of off-gassing and odors. Exercise the smell patch test with care following the details of the procedure and it should be helpful. Let me know what you find.

On 2018-12-01 by Sandra

We are in the process of trying to eliminate the source of an odor In our home.

We've removed carpet and padding that we thought was the source due to a cat and sealed the flooring with a liquid sealer. We had our crawl space reinspected where mold has been remediated and the crawl space was encased. That was done 18 months ago and did eliminate the odor we were experiencing.

We had vinyl plank flooring installed in our family room, adjoining dining room and kitchen this spring. After reading articles trying to figure out this mystery of another odor that is just consuming my life right now, I found several articles that the vinyl plank flooring could be the cause.

The odor is permeating our furniture. I have begun bagging our clean clothing, again. I used to do the same before the mold remediation. It's become a real problem.

I will be doing the smell patch test and looking for the manufacturer of the flooring to contact.

Have you had others with similar problems? Any advice would be very appreciated.
Thanks!

On 2018-09-02 by (mod) - island sink stinks

Look for a vacuum breaker vent that is commonly used at island sinks - yours may have failed and may be releasing sewer gases.

See ISLAND SINK PLUMBING VENTS at https://inspectapedia.com/plumbing/Island_Sink_Plumbing.php

On 2018-09-02 by Shirlyne Meeks

We have a center island that started emitting a bad smell. It does not have a sink. The dished and pans that I stored in this island take on the smell. It has gradually become stronger. We have had three plumbers that have checked our clean water line and the slab for leaks. Nothing came up. Our kitchen sink is also an island sink.

It is about 3 feet from the island that has the odor. The kitchen sink does not have the bad odor under it. It has a P-trap for venting.

We cut holes in the lower shelf in the island so we could look inside. The cement is dry and no mold is evident. What do you suggest? our house is 17 years old. We bought it new.

On 2018-06-13 by Anonymous - shades are offgassing a Body Odor smell?

@Steve,
Have you had any new shades installed if you read my post it is definitely from the shades room darking when they heat up it releases a chemical smell or a BO smell, yess BO!!

So anything vinal,thats new,casing on vinal windows that where the smell usually comes from called off gassing. Hope this helps,check the internet so much info the smell is the chemical they use ,its natrual shades for me next time lol
Good luck lorraine

On 2017-10-12 by (mod) - four seasons room that has a mysterious odor

That the particulate mask is diagnostic or at least suggestive that particles are involved in the reaction you suffer.

I've had that response when there is a local mold contamination problem as well as when there is contamination from insects such as cockroaches, or dust mites, or pet allergens (among the most-common issues).

Perhaps you're smelling MVOCs from a mold reservoir. I'd start by looking for a history of leaks that may have wet insulation and wall or ceiling coverings.

On 2017-10-12 by Steve

We have a four seasons room that has a mysterious odor that I severely react to causing bronchial spasms and/or asthma type of attacks. I have had to go to the ER two times for breathing treatments for relief.

I have been wearing a particulate mask while in the room which helps tremendously. The odor is hard to describe, but best description is that it is somewhere around a acetone smell to a formaldihyde odor.

It comes and goes day to day, and varies in its severity. My wife has said she has noticed an odor in the room, however at a lower intensity than what I am reporting.

She also suffers no major breathing problems, however does have intense sneezing spells from time to time. We have changed the floor covering four times, starting with carpet tiles, then to vinyl laminate flooring, now to a wood product laminate flooring. the odor has not decreased or changed in any way with the flooring choices we have tried.

The room is 14' x 14' and is off of a dining room. You can start smelling the odor when leaving the dining room. The room has four patio chairs with aftermarket cushions. I have buried my nose in the cushions and do not notice any odor coming from them. What should I do next?

On 2017-08-01 by (mod) - off-gassing solutions and times

Lorraine,

For this sort of problem things often settle out into one of two courses of action. Either


heat drives off enough volatile that the plastic material stops making a terrible odor, in which case ventilation with fresh air and the occupied space will help,

or some products continue to off-gas for a very long time depending on their chemical formula, and may need to be changed.

On 2017-07-31 by Lorraine - smell from sun block vinyl shades

Recently had a new sun block vinyl shades installed when the sun is beating down through the windows a chemical smell is being released in my whole condo unit I know it is from the newly installed shades which are approximately 6 feet tall we have very high windows in our units

i'm just trying to help any others to please be aware that once they heat up because of the sun beating down on them the shade does release a chemical smell especially if the shades are new

I am in the process of reaching out to Three Day Blinds who did the installation and waiting for them to get back to me I don't know what recourse can be taken, once I have a solution I will post on what steps were taken to eliminate that chemical smell

On 2016-11-29 by (mod) - where is the odor source

As you are sure the smell source originates in walls, it might be more effective to investigate the wall cavity and wall materials for the odor source.

Spraying a sanitizer on flooring won't remove a wall odor source.

If there is access below the floor, look there as well.

On 2016-11-29 by Al - Sprayed concrobium on floor

Had carpet installed in basement a year after moving in to new house.

About 10 years later musty smell started moving into the carpet from outside walls (cement floor and walls).Started getting headaches, sore throats, coughing, ect. Never had water but basement is humid. Removed carpet and underlay, no visible signs of mold just the smell.

Sprayed concrobium on floor, installed new underlay and carpet. Now (2 years later) noticed the smell is returning. Any solutions/suggestions?

On 2016-10-08 by Anonymous atomic powered fabric softener

We live in a large apartment complex and the neighbor downstairs is using atomic powered fabric softener and my bedroom reeks and even our laundry room above hers and any clothes I have hanging in there to dry end up reeking of this weird sweet smell. She does this on Sunday so I am dreading the next one.

The maintenance man said he smells nothing !!! Help me.

On 2016-10-08 by Taylor Hayes NEW vertical blinds in our apartment and they smell bad,

We have NEW vertical blinds in our apartment and they smell bad, though not like new plastic. I notice it in the morning when I get up and walk into the living room. It has been 2 wks so maybe I should just wait longer for them to air ou

On 2016-04-18 by (mod) -

Re-posting without disallowed advertisement

Yemi A. said:
Odors can be a big problem especially when the source is difficult to identify.

On 2016-03-17 by (mod) - horrible odor that comes & goes

Carl

Unfortunately "thick chemical odor" is not specific enough to be diagnostic. The best approach is to try to track the odor to its source. You may need help with someone with a fresh, sensitive odor sensibility.

On 2016-03-10 by Carl wilson

Live in a large apt bldg & have been smelling a horrible odor that comes & goes is making me really sick - nausea, headaches. It smells like anesthesia/dentists office, very sweet, thick chemical odor. Done lots of web searches but nothing comes up.

It's a rental and the management is totally incompetent so it's up to me to find source & try to get them to fix. They'll NEVER investigate it. Does this sound familiar to anyone?

On 2016-01-06 by (mod) - horrible odor that comes & goes

If you did not change any ductwork it is natural to suspect the new heat pump; however if only the outdoor unit was replaced I doubt that it's at fault;

I'd ask for a complete inspection of the ductwork looking for signs that something leaked into the duct system or into the air handler, or that an animal got into the ductwork.

Also check for an odor source near the air return registers.

Beyond those tips and the suggestions in the article above we'd need to know more about the home and its HVAC to speculate in more detail.

On 2016-01-06 by M. Ham

We have an odor coming out of our air vents which began about six months after we had a new Trane heat pump installed.It was not present all the time.

Even though, it is not always present, it seems our house now has a constant not so pleasant odor. Where do we begin to determine where the odor

On 2015-11-21 by (mod) - sweet chemical smell

Rob:

Unfortunately, there is no single, simple, low-cost test that can screen a building to identify all possible odor sources nor the odor chemistry to pin down the odor source.

I think it will be more productive to narrow down the odor source. It's unlikely that the actual source is uniformly distributed throughout the home, even if you smell it widely.

Try closing doors, isolating building areas, ventilating areas, and seeing where the smell is strongest. Those will be areas to try the test procedure outlined in the article above.

On 2015-11-21 by (mod) - new house smell has not gone away

RE-posting comment

AUTHOR:Rob O (no email)

COMMENT:Our house was built 3 years ago. We moved in 2 years ago. It had a smell to it be we assumed it was due to just being given built. The smell has not gone away. It permeates everything in the house but originates In the basement.

It's not mold, mildew, septic, gas, or any biological. It is a sweet chemical smell. We've had 2 home air quality professionals come to the house and either of them was familiar with the smell.

The first guy never came back and the second guy says he can't help us. I'm concerned for the health of wife, pet and myself. Any suggestions would be appreciated.

On 2015-09-23 by (mod) - odor generated from some mysterious source

Indeed if an odor has penetrated many building materials tracking down the source can be difficult; you might have success using the smell patch test described above if you get help from someone with a sensitive sense of smell, keeping that person outside in fresh air and giving them only 2-4 samples to smell in any given interval.

Beyond that the ability to discriminate the "most strong" odor sample will diminish.

On 2015-09-23 by kaptain k- odor generated from some mysterious source inside of my apartment

I have an odor generated from some mysterious source inside of my apartment, which is an old gun shop converted into an apartment dwelling; this odor is emanating from some substrate (or, building material/surface) and it's driving me absolutely NUTS, because I cannot determine where it's coming from, in terms of a SPECIFIC ORIGIN! I've been investigating this strange odor for weeks now, to no avail. It is NOT organic in nature; it is more of a toxic building material-type of smell -- not from adhesives, either.

Can green board cause anything like this? (I've never known this to occur, personally.)

Or, could I possibly be having some (odor) issue occurring under the slab (single story) of this unit? It's built on top of standard 4-inch concrete slab, w/ gravel "crush-n-run" underneath. I live close to a rail line and a foundry -- VERY close, in fact. This odor continually wafts around the interior spaces; this is a SMALL apartment unit, of masonry/concrete bock construction; conventional F/G insulation,

with added insulation (by me) above kitchen (newly-installed "drop"-ceiling); the apartment unit is roughly 500 sq. ft.; it's an "addition" to a larger frame home (built about 50 years ago); this converted apartment unit (added-on about 15 years later) adjoins the main structure (a single-family frame home)... BTW; everything (in terms of construction materials, methods, and styles) is what can be referred to as "standard building practices".

Again, this odd odor has got me stymied-- I am simply vexed, in terms of figuring out its source... even worse, is the fact that now this maddening odor seems to have seeped into ALL surfaces, my clothes (hanging in closet) now have this smell; all the walls (painted and raw green board surfaces now have this smell; my window-mounted air-conditioner reeks of it (due to circulating the air with the odor impregnated in it...

I mean, practically everything last damned surface and item in this apartment NOW smells of this baffling odor!
I'm desperate for some help on this!

On 2015-07-24 by (mod) -

Sealing air leaks between building areas might reduce odor transmission between them as you suggest.

On 2015-07-24 by Chemical pesticide odor in condo

I live in a raised raised lovely condo 2nd floor unit. Someone has been applying a pesticide two to three time per week from Apr to Jul 2015. The smell is concentrated in the master bedroom which is next to the firewall, which is next to the town home next door and above the first floor unit with the same layout the I have

. I checked with the neighbor downstairs and she had the smell in the same location for days. Last week I went to her home to see if the smell was there but it was gone - still in my master bedroom though.

Last night, around 4:00 am I awoke to my nose burning and dry. It was awful. Do you know of pesticides that smell like burning charcoal or steel/old keys? I will try your foil, paper towel test. It has to be the neighbor next door or downstairs applying pesticides/chemicals.

The neighbor next door in the townhouse came over to smell and said it smells like a convalescent, nursing home. I have never been to a nursing home since my mom and 99 year old nana were taken care of at home,

The smell is only in a 4foot section of my bedroom against the fire wall. The property manager says that no one in maintenance applied any pesticides or chemicals, but, whenever I tell him about the awful smell, the scent dissipates for a few days.

Today, I was pulling into my garage and the neighbor next door was in his garage trying to listen to my conversation with another neighbor. When I walked toward his garage, he closed the door.

Guilty! I have heard drilling and movement in the attic and door slams. Condo attics are connected and separated by drywall fire board, which can be cut opened if a creep wanted to do so. Sorry, I'm regressing. Note: I ordered a surveillance camera for the attic and a scuttle access door witho a lock, since I heard the drilling and movement (not an animal).

There was a leak in the roof that was repaired and a rodent problem which has been resolved. Would sealing around the floor/carpet, where the smell is located, stop the smell?

On 2015-07-17 by (mod) - test air quality for smoke and fumes caused by smoking meat and fish

Lynne

Without having to perform a rather costly spetrographic analysis of the molecules trapped in an air sampling filter or cassette I'd look for carbon.

On 2015-07-16 by Lynne Cronk

How do you test air quality for smoke and fumes caused by smoking meat and fish

On 2015-01-24 by Marylou

Live in attached housing and for the past year, smell cigarette smoke in room on first floor and room on second floor. Units are separated by cinder block walls.

On 2014-11-04 by (mod) - know the identity of an odor and track it down

When we don't know the identity of an odor and need to track it down the best bet is to use someone who has a sharp sense of smell to help locate where the odor is strongest.

Consider a dead animal can be in a crawl area, wall cavity, ceiling cavity etc.

Consider possible prior chemical sprays or treatments too.

You can also try keeping an odor log to see how the odor relates to time, weather, operation of mechanicals, etc.

On 2014-11-04 by Ernie - odor that I can''t seem to identify

Iam looking at buying a 35 year old modular home and there is an odor that I can''t seem to identify. It is a not musty or wet smell and not a chemical smell nor a septic smell more along the lines of dead animal and yet not that gross.

As soon as you step inside from a basement entrance or an upper level door it hits you and within a minute or so you can't notice any more unless you step outside and then back in. There are no pets or evidence of rodents and it doesn't penetrate fabric. We have searched basement to attic and there is no dampness at all or anything else that smells.

There is an oil furnace and no propane or gas?
I'm completely stumped. Any idea what it might be coming from?

On 2014-10-06 by (mod) - you couldn't really smell inside but when you left you could smell it on your clothes

Steve

It's worth taking the time and trouble to get a more accurate idea of the odor source as that will dictate the repair needed. But some cheap easy steps might include putting down poly on a dirt crawl space floor and making sure there is no mold contamination nor dead animals therein.

On 2014-10-02 by Steve B

We have a rental house we purchased 10 years ago. When we bought it there was a strange smell that you couldn't really smell inside but when you left you could smell it on your clothes. We chalked it up to the previous owner smoking. We washed all the walls with TSP and repainted everything inside and put down new carpet. Our tenant was also a smoker and recently moved on.

We are inside working now and the smell is there again. All you have to do is be in the house for about 10 mins. and you can smell it on your clothes. I have found several areas where air from the crawl space can get into the living area and I am working on sealing those up, but even with airing the place out big time your clothes still stink when you leave. Any ideas...it's driving me nuts.

On 2014-09-06 by (mod) - odor in a upstairs bathroom when we take a shower

Bill, in the ARTICLE INDEX see SEWER GAS ODORS

On 2014-09-03 by Bill S

I get an odor in a upstairs bathroom when we take a shower, I have drain issues, the pipes are clear. The smell is like something die and it comes and goes. How do I locate the spot where the odor is coming from?

On 2014-04-28 by (mod) - smell of wires burning

Joon,
I don't know but often the smell of wires burning is fairly distinctive - I'd be concerned about finding or trying to rule out

Watch out: wires burning = an unsafe electrical circuit or component. Risking fire or shock.

On 2014-04-27 by Joon

Hi, In my house, there is smell of wires burning in only one vent in a second floor bedroom and there is same smell in basement when gas furnace is running. No smell from other vents in first floor and other floor. Smell is gone when I turn on air conditioning. What could cause it? Any idea?

...

Continue reading at SMELL PATCH TEST to FIND ODOR SOURCE - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Odor & Gas Source Detection Articles

• GAS DETECTION INSTRUMENTS - home
• COLORIMETRIC GAS DETECTION TUBES
• CONVERT PPM to % CONCENTRATION
• Drager GAS DETECTORS
• FIRE OFF-GASSING HAZARD DETECTION
• EMERGENCY RESPONSE, IAQ, GAS, MOLD
• GAS DETECTOR WARNINGS
• GAS EXPOSURE SCREENING TEST
• ODORS GASES SMELLS, DIAGNOSIS & CURE - home
• ODOR DIAGNOSIS CHECKLIST, PROCEDURE
• ODOR DIAGNOSIS SIX STEPS - taking an orderly approach to odor source tracking
• SMELL PATCH TEST to FIND ODOR SOURCE
• TIF 5000 GAS DETECTOR
• TIF 8800 GAS DETECTOR

 

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SMELL PATCH TEST to FIND ODOR SOURCE FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING ODOR DIAGNOSIS & CURE

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