InspectAPedia®   -   Search InspectApedia

Collapsing building © Daniel FriedmanSources of chemical smells or odors in or near buildings

Chemical odors in or near residential buildings: this article describes clues, focused on common sources of building chemical smells or chemical-like odors, that any home owner, home inspector, or other investigator can follow in seeking to pinpoint the source of an annoying or obnoxious odor in buildings.

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

Checklist for Diagnosing the Cause of Chemical Smells in buildings

Odor absorber on display rack (C) InspectApediaOften people's perception of odors varies with time and exposure or with a number of other site factors that make it hard to track down just where a smell is coming from.

But if we think carefully about when, and under what conditions we notice odors, often that information is instrumental in tracking down an odor to its source and thus in helping us decide if an odor refers to a potentially dangerous or unhealthy condition.

Photo at left: Air Sponge™ is an odor absorber product for sale at a building supply store and described by the manufacturer as effective in areas up to 300 sq. ft.

In our opinion no odor absorbing product can handle a troublesome building odor problem in a building if the odor source is not found and removed.

Using dust removal as an analogy, imagine waving a vacuum cleaner wand in the air in your kitchen in hopes that the dust bunnies under the living room couch will somehow be removed.

A principal ingredient in many such odor-absorbing products is sodium bicarbonate - (baking soda) - a hygroscopic material that readily absorbs moisture from the air and that may absorb some odor molecules as well [22].

But because an odor reservoir, like a mold or dust reservoir in a building, can produce effectively a continuous source of smell, the most effective way to remove a building odor is to find and correct its source.

This building chemical odor source list is in simple alphabetic order, not in order of probable cause, importance, or health risk, all of which can vary widely.

Keep a Building Chemical Odor or Chemical Smell Diagnostic Log: Use any of the files listed below to record various data that can help figure out the source of a mystery odor or smell - we recommend the first Odor Checklist Form listed below as it is the most detailed version.

 




ADVERTISEMENT





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 2021-11-28 by Inspectapedia Com Moderator

Carly,,

Before running through a building with an axe chopping out walls, a useful approach is to identify the most-at-risk points where there could have been leaks into walls, floors, ceilings,

and to make small inspection openings in the most-suspect places to see what you find.

That is a reasonable approach can provide some empirical evidence on which to base a decision on whether or not further actual demolition is justified.

On 2021-11-28 by Carly

@Inspectapedia Com Moderator,

we didn’t gut the bathroom down to the studs. We did replace the sink and toilet, floors and baseboards and repainted but the smell is still there.

We have exhausted all other except for gutting the drywall down to the studs. Frankly not sure we can afford that.

City sewer guys came and an expert plumber came and they say it’s nothing to do the sewer or plumbing.

After 6 months the smell is still there and as strong as ever. I can’t imagine what could smell that strong without diminishing.

And the smell also travels to the room above even though the bathroom has no heating vent. It does have an exhaust fan but that goes out the side of the house to outside. So it must be something behind the wall but what could smell that strong without diminishing?! I’m so frustrated I’m ready to move.

On 2021-11-21 by Inspectapedia Com Moderator

@Carly,

Yes we'll do it sounds unusual. Typically with a cleaning product as used for example in a toilet by the time a toilet is flushed the chemical of the cleaner is dilute.

As you completely gutted the bathroom down to the framing, which is what I infer from your note, I would think that you would also be able to see if there was evidence of a history of leaks there including perhaps leaks into the walls - that might show up at the wall floor juncture, or in a ceiling below.

From your description I don't know offhand what else I would explore other than the drain system and the history of the use of chemicals and cleaners in the building.

Adding: You haven't mentioned the heating system and whether or not it's possible that odors are being transported from one location to another.

On 2021-11-21 by Carly

@Inspectapedia Com Moderator,

We replaced everything in the bathroom. New toilet, sink, floor, baseboards. The smell is still there. Is a very strong chemical perfume smell like in a blue loo / port a potty.

It can also be smelt in the bedroom above the bathroom.

Could it be a previous cleaning product used leaking out of a leaky or loose pipe or vent pipe behind the wall?

On 2021-11-20 by Inspectapedia Com Moderator

@Carly,

I would look for recent use of a cleanser, deodorant, toilet treatment, or spill in the powder room where odor is strongest.

More details and suggestions are above on this page and in this article series.

On 2021-11-20 by Carly

Small powder room (toilet and sink, no window, exhaust fan that vents outside) has strong bad chemical smell. Smell can also be smelt in bedroom above powder room but not as strong.

Smell us not coming from toilet or sink. Not sewer smell. Reminds me of the chemical smell in port a potty/blue loo. Please help!

On 2021-08-06 by Inspectapedia Com Moderator

@Marjorie,

If a pesticide has been applied improperly in your apartment it could be hazardous to your health;

If fresh air ventilation doesn't cure the problem promptly you may want to go outside or to another apartment to contact your landlord to let them know of the problem and to find out who may have applied what pesticide, when;

both you and building management have a great interest in being sure that any chemicals or pesticides used at the property have been used correctly and safely.

On 2021-08-06 by Marjorie

My apartment smells like pestisde, what should I do?

On 2021-06-21 by Inspectapedia Com Moderator - Environmental or safety or health concerns need to be addressed

@Lorraine M,
Thank you for your question

I certainly respect and share your concern for the health and safety of your grandson so please don't misconstrue the cautions that I must cite.

1. I'm not aware of any medically accepted, certified, reliable "toxic chemical exposure screening test" that you might have had done and therefore can't interpret nor even understand the 90% number that you cite.

Frankly I just don't know what that test result says it means and I don't know if we can trust it to be meaningful.

On the very surface of it, it seems irrational to me to give a simple percentage number as "toxic exposure" when there is no simple screening test for all of the thousands of possible or even likely harmful chemicals that can be present in an environment.

Instead a test, which is a blood test or urine test, would look for specific chemicals or families of chemicals or contaminants’ family name. Therefore without more specifics a simple number has no meaning.

In fact even if a specific test showed that an individual had for example harmful levels of a chemical in their blood, we wouldn't know without more investigation where are those originated or where the person was exposed to them. It's both dangerous and expensive to work up the wrong toxic chemical tree.

2. You could consider hiring a professional home inspector or building inspector who is familiar with safety hazards and who would agree to look for and report both safety hazards on your property and chemical hazards such as bottles and containers of pesticides or evidence of prior application of such chemicals on surfaces are in locations with which a person could come in contact.

I know that they are less frightening that invisible chemicals that we can't see, but the fact is that the greatest dangers to people our children are much more mundane things like unsafe steps and rails or failure to fasten the seat belt or smoking or being around people who smoke. If we don't address those things first these other concerns have little meaning.

Worse still, we may in fact increase the level of danger by making ourselves feel safe because we addressed very unlikely hazards while at the same time we have unfortunately, ignored far more likely hazards.

3. If you smell chemical odors at your property then there is very likely to be an actual source.
Perhaps that garage.

It's not a useful argument for one person to claim that because they don't smell something nothing is present. Individuals' sense of smell varies enormously from one person to another and even within the same person depending on their state of health.

If you know that there are harmful chemicals in your garage and you can smell them in your yard or in your house then you have an environmental cleanup project that needs to be done to protect the health of everyone.

4. You should discuss your concerns with your grandchild's parents and perhaps they in turn with the child's pediatrician to ask if there are specific reasons to have specific environmental or safety or health concerns that need to be addressed. Find a doctor whom you trust and take the doctor's advice.

On 2021-06-21 by Lorraine M

I had a toxic chemicals screening lab test my grandson, 7yrs old. His levels were in the 90% range for toxic chemicals found in industrial areas.

The only exposure he has had is being outside in our yard. He is not allowed in the garage. My husband has a garage not over 14 ft from our home where my grandson lives.

When you step outside our home you can smell the garage odors.

My husband has solvents, paints, thinners, gasoline , liquids of various kinds. Dirty rags and papers. He says he cannot smell anything. Also he does smoke cigarettes and cigars while in his garage.

Who or where do I call for help? This is a grave concern for our daughter and especially the health of my grandson. Thank you.

On 2021-02-12 by (mod)

Lisa

That sounds as if there could be a health concern and - speculating: perhaps an improper cleaning or other chemical activity; you might see if your building owner or your health department is interested in giving a hand.

On 2021-02-12 by Lisa

I live in a walk up apartment with fire doors at the entry of each hall way. For the last three nights I have noticed a very strong chemical smell in the hallway which dissipates early in the morning and is entirely nonexistent during daylight hours. Woke up about 1 AM from a lot of sleep recovering from being sick and the chemical smells really strong.

On 2020-09-03 by (mod)

Cindy,

With your AC ductwork under the house it seems unlikely that you would be drawing roof odors into the building. I would start with an inspection of the crawl area and up the ducts themselves and also look for a spill or odor source near your return air inlets

On 2020-09-03 by Cindy

I had a new shingled roof installed in September of 2019 due to storm damage.

Starting in April I noticed a strong chemical smell in my house that has been getting worse and worse. I live in Arizona so I am guessing the extreme heat baking the house and new shingles and the odor is drawn into the house by the AC.

I live in a manufactured home and all the AC duct work is under the house etc.

Could it be the new shingles causing this horrible smell and if so how can I get rid of it? Would the roofing company have any liability in this?

On 2020-06-06 by danjoefriedman

Neighbor

Check with your local building department.

If your neighbors are in a residential property and are conducting a business it may be that they are not permitted to do so.

Also if they're doing something that's unsafe or hazardous in the neighborhood, your building department should have an opinion about that.

On 2020-06-04 by Neighbor

My neighbors have a corrugated metal 1 level structure in their yard where they drill and create a lot of noise. They even found a way to get the buzz into my computer sound equipment.

But, they also blow out some type of very toxic gassy odor. It's like a varnish, fuel, paint...I don't know but it's so powerful that it comes over 100 feet to my yard/back door and into my house.

I had to close my door again today because they ran whatever it is for only a couple of minutes when I was watering my trees out back and the toxic fumes of it was even into my front yard almost 200 ft.

I was instructed to call 911 if it happens again because it not only was so toxic I came in to shower but it has a lingering chemical taste and odor in my mouth, nose and my eye felt a slight burn.

There has to be a code to shut them down right?

On 2020-03-03 1 by (mod) - extractor fans increase indoor odors

Steven

Unfortunately those extractor fans you're running may be making matters worse by creating a pressure differential that is actually drawing more of the odor - whatever it is - from its source into your own occupied space.

A temporary fix that would also be diagnostic would be to reverse the system. Try a fresh air inlet fan that brings fresh air into the occupied space, slightly pressureizing it.

On 2020-03-03 by Steven

I'm at my wit's end.
We have a disgusting odor coming from the false ceiling of the bathroom. It's a condo.
Inside the ceiling is an extractor fan, which pumps air outside on the balcony...

Don't think this is leaky as no odor appears to come from the fan.

Also inside the ceiling are various pipes water ones I guess and ones that run through the top to bottom of the whole building. It's pretty small, maybe 2 feet height and 2.5 x 2.5 meters roughly although not an exact square.

I got a air quality meter which shows HCHO and TVOCs, as since I've lived here I keep getting sinus problems, throat issues, reoccurring lots, and now I'm allergic to loads of foods I've always eaten, so I figured to check things. The air quality is often tines 8 or more times the WHO recommended level of TVOC Indoors, 0.500 mg/m3.

Have 2 extractor fans on most of the time now and the back window open otherwise if all shut up it's unbearable, makes me dizzy, even start losing my voice.

Even my girlfriend is noticing effects and she is like the Terminator, rarely ever I'll.

Have told the admin but they just dismissed it as a fresh smell, and basically treated me like I'm crazy, even with the air quality meter.

Have even had nano titanium dioxide coating done and this hasn't helped either.

When you open the holes to the ceiling the smell just wacks your in the face it's so strong and blatently chemicals. It's like the epoxy or stuff they use to seal pipes but if it's been built 3 years ago how is the smell still so strong?!

It's so strong it's seeping through the drywall false ceiling. I'm gonna paint it again and then seal it with several coats of some PU coating (all low or no VOC) but I fear that's not really solving the issue, plus the holes for the aircon pipes I'm not sure they are sealed 100% so the smell will still leak out another way.

Anyone have similar issue, and his can this be resolved? Thanks for any advise

On 2019-07-21 - by (mod) -

Soaked carpets are usually tossed out;

On 2019-07-21 by Veta

I noticed in my basement that an old rug that i placed there on the floor was soaking wet and i dont know where it was coming from
It had a funny odor like a spoiled or egg or vomit smell. It was also in another area.

I mopped the area with kitchen cleanser powder and it left a clear sticky like film. I placed the rug remnant in the outside garbage in a white plastic bag. What do you think this wetspot film could be. It also seems to be on my curtains as well.

On 2019-05-17 - by (mod) -

Try the oldor diagnostic procedure given at the continue reading link just above. Let us know how that works for you.

On 2019-05-16 by Eileen

I can’t figure out what the chemical odor in my house is. I’ve checked furnace mold testing. Plumbing. I really notice it in my nose after I leave home. Help please.

On 2019-05-16 - by (mod) -

Thomas

We know that individuals' sense of smell or sensitivity varies widely, but if this odor persists you might need to find some others who will corroborate your complaint.

On 2019-05-10 by Thomas

I am a resident at a dorm. The past few days in the indoor courtyard I have smelled a smell very similar to antifreeze. Some areas are stronger than others. Staff doesnt seem to care

On 2019-03-12 by Jo

Hi, we renovated our house about 13 years ago and moved in post renovation.

Prior to this, tenants lived in the house and it was mostly carpeted etc. It is an Edwardian weatherboard home built in 1907. It was completely gutted and re-plastered using standard plaster board. The floors were replaced with Tasmanian oak that was stained to a walnut colour.

I believe the stain was mixed into the top/finishing coat. It is a matte finished polyurethane.

Standard Dulux paint was used on the walls and standard fibreglass pink bats were also used as insulation in the walls and roof. Since we have moved in all those years ago, the house has a sweet smelling chemical odour. It has not reduced at all in 13 years and is of concern to me.

It is most noticeable when the house has been shut up for a few days and also when it is hot. When we return from being away somewhere and we open the door, it is very strong all through the house.

We find it hard to isolate the smell because it is everywhere. I think we also get used to the smell, but when you are coming in and out it does get some airing and it reduces etc. We also have evaporative cooling that has an option for just putting on a vent and sending fresh air through the house. I use this a lot in summer just to keep the air flowing.

Anyway, we are at our wits end trying to work out how to fix it/where it is coming from. We don't have any plastic window coverings, kitchen benches have mdf under stone bench tops but that doesn't seem to smell.

We have hydronic heating. It's doesn't smell like mould or rising damp. Anyway, if you have any thoughts I would be most grateful. Kind regards, Jo.

On 2019-02-21 - by (mod) - odors from home made "slime"

Catrina,

I don't know what materials your daughter used to make slime at home - that'd be a good place to start thinking about what may be spilled or jammed in a closet or under a bed.

The usual ingredients for home made "slime" are
School glue
Borax (Sodium tetraborate)
Food coloring (optional)
Water

None of those ought to be particularly smelly

I'm not sure how to characterize the odor from your description.

YOu might try the ARTICLE INDEX to find our procedure for SMELL PATCH TEST - that lets you track down an odor to an emittting surface

You might also ask if there were any spills that might have leaked into a floor or into the bottom of a wall cavity

On 2019-02-20 by Catrina

My daughter started making slime about a year ago but the new forms and kinds got a bit tricky. She used the school glue, baking soda, contact solution, air freshener, fabric softener but not all in combo.
I have cleaned her room from top to bottom. Only her room has a gassy headache breath taking odor. We have baking soda in a up to absorb the odor. Any ideas?

Reader Question: Acetone Smells in Well Water

(Oct 17, 2014) KAREN VAN ESSA said:

For the first time in 10 years I can smell acetone intermittently in my cold water, which comes from a drilled well 130 feet deep. I have had the water tested for a broad range of chemicals at least twice before: levels were below all guidelines, except for sulphur and hardness, but the levels are tolerable and I have no water softener.

There has been no construction in my rural neighbourhood, the nearest house is 500 feet away, and the only industrial site is a car wreckers/body shop about 1/2 a mile away whose owner is semi-retired.The land has not been farmed for at least 25 years. What could be the source of this volatile? Could it be natural? (this is a mainly wooded area with small streams and ponds)

Reply:

Karen

Acetone would not be associated with a septic system failure or odor problem -
[ this question was originally posted at SEPTIC SYSTEM ODOR CURES]

I would begin with a lab test to identify what's actually in the water supply. Knowing that accurately will help pinpoint possible sources.

Acetone in well water research citations

the latter also discuss chlorobenzenes

Reader Question: Chemical odors, air fresheners, ozone, secondary air pollutant hazards: I can't pin down the source of a chemical odor in my house. Any suggestions?

I was just looking at your web site hoping to find some answers for my problem and didn't really see what I was looking for. I'm hoping you can make a suggestion or point me in the right direction.

I've been chasing an odor around my house for almost a year now and can't seem to pin it down. What it is or where it is coming from.

I've had a plumber come to my house, HVAC person, local gas company, city sewer people, and talked to a "mold" guy although I didn't have him come to my house. I bought my house new eight years ago and it's only 1100 sq. ft. and I don't find any evidence of water damage that would precipitate a mold situation.

The smell has a chemical nature to it that I think is now starting to cause some health concerns for me. Since I've pretty much weeded out all of the obvious things about all that is left is....my next door neighbor cooking drugs of some type.

've filed several reports with the local police department and done several other things as well. Law enforcement may or may not be investigating the situation. They don't really say anything one way or the other.

It seems to me that I need some way to determine exactly what the odor in my house is; but I don't know how to go about it.

Everyone that I've spoken to can check for things like sewer gas or mold spores but trying to ferret out the ingredients that might be used for cooking drugs is a whole different ball game.

Not really that easy as far as I can tell. I've seen some electronic equipment on-line that is for sampling for residue inside houses where drugs have been cooked but that's like a first-hand situation. My situation is more like a second-hand smoke deal.

Please let me know if you have any suggestions. I'm pretty desperate at this point. - R.E.

I have an office attached to my home which is outgassing from an unknown source. Possible culprits are formaldehyde from an air freshener concentrate spill or perhaps hard foam ceiling insulation. Any suggestions on how to identify the nature of the gas and what to do about it - Lawrence Jackson 3/28/12

Reply: Visual inspection of materials and building condition and a series of smell patch tests might help; secondary air pollutants from air fresheners & ozone generators

Lawrence:

Since tests to capture a gas and then identify it can be costly to arrange, it makes sense first to trace the odor to its source - often what you see there will be diagnostic. But I and experts agree that an indoor "air freshener" (such as the plug-in type) can in fact be a source of secondary pollutants, and we agree that some indoor air fresheners include a small amount of formaldehyde, typically 0.1%, to keep the air freshener from growing organisms.[8] Also

see OZONE WARNINGS Use of Ozone as a "mold" remedy is ineffective and may be dangerous.

Too often an air freshener is not really removing anything from the air to make it more "fresh" - rather it is adding chemicals that cover up the original odor (leaving it in place) and/or chemicals that deaden your sense of smell so you just don't notice the original odor.

These concerns for secondary air pollutants can be even more severe if people try using ozone generators in the same location. [6][7][8][9][10]

A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem and in this particular case s/he might quickly spot something known to be a common source of problem odors but that had remained unfamiliar to you and some of the others who've looked. With no specific information about your building, I can only suggest a general approach to tracking down the odor problem.

That said, here are some things to consider:

Separate probable emergencies from other odor problems

Of course some odors are widely recognized by many people and some of these (fuel gas odors, methane, sewer gases, even flue gases) can be indicators of very dangerous conditions that need prompt action.

Sophisticated tests to identify gases and chemicals in buildings

There are gas testing methods that can identify the chemical constituents of gases (or in other words odors) found in buildings and elsewhere using a combination of a vacuum canister to collect air samples and mass spectrometry and similar instruments.

Industrial hygienists are equipped and familiar with these procedures, but I'd be careful: most of the hygienists in my association (AIHA) are industrial experts and only a smaller number are familiar with residential buildings and with the building science needed to understand and diagnose and cure odors in residential homes.

But for other smells in general I am reluctant to order gas and chemical tests to "identify" an odor for several reasons

An odor or smell may be the mix of a number of chemicals produced by a particular building product or condition. Identifying the specific chemical constituents of the gas often fails to point to the actual source in a building.

I have found inconsistent results from test labs and on occasion even large expensive labs have returned poorly-developed and unreliable results. It seemed to depend on luck of the draw about which technician and supervisor actually handled the work.

A chemical signature that identifies odor components might suggest a direction of investigation but equally frequently in my experience tests of air or gases in buildings are not sufficiently diagnostic.

The results may confirm an odor while taking very limited or no steps at all towards identifying the odor source and no steps whatsoever in guiding the building owner into a plan of action.

These tests tend to be specific in target and expensive in use.

Suggestions for tracking down smells in residential buildings

I have had best results in tracking down and eliminating odor problems in buildings by using various measures to pinpoint the actual physical odor source. When the source is recognized we usually will know quickly just what the material is or just why the odor is occurring.

There are other helpful variables to consider that also help track down an odor source such as the correlation of odors to weather, wind, moisture, temperature, sunlight, sun exposure to different building areas, time of day, operation of various equipment etc.

For sources more far afield it's sometimes important to make sure that the odor is originating inside the building not elsewhere.

For odor complaints that are not observed by everyone in the building, because individual sensitivity to odors and chemicals can vary widely I don't assume that the "non-smellers" are correct (that there is no problem) but I have encountered cases in which a medical or even neurological condition was involved.

Use a combination of people with a good sense of smell and the smell test to see if you can identify where, when, and under what conditions the problem odors are strongest.


...

Continue reading at ODOR DIAGNOSIS CHECKLIST, PROCEDURE or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see CHEMICAL ODOR SOURCE CHECKLIST FAQs - questions & answers posted originally on this page.

Or see these

Recommended Articles

Suggested citation for this web page

CHEMICAL ODOR SOURCES at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or see this

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

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification
when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Comment Form is loading comments...

Citations & References

In addition to any citations in the article above, a full list is available on request.



ADVERTISEMENT