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Smell test last step (C) Daniel FriedmanSmell Patch Test
How to Track Down a Building Odor to a Specific Material or Source

Smell patch test procedure tracks down odor sources:

How to use paper towels, aluminum foil, and tape to perform a simple but effective odor source test of building surfaces and materials.

This article 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.

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

How can I Track an Indoor Odor to its Source?

Smell test setup (C) Daniel FriedmanThe procedure we describe here is easy, inexpensive, and fast - you'll need a day or so, plus some common household materials to track down an indoor smell to the surface or material that is its most likely source.

Depending on what caused the material to smell in the first place, disposal may be the only option. In other cases, amateur or professional cleaning or use of sealant paints may be effective. If you've already tried using an ozone generator to kill an indoor odor, you may have used the equipment improperly.

Ozone or O3 is a highly reactive oxygen molecule that can cause oxidation of materials that it touches. This oxidation, especially of some rubbers and plastics, can leave a horrible smell in the treated building.

Before getting into the details of how to perform the smell patch test, note that there are at least the following odor investigation approaches:

4 Odor Diagnosis Strategies

You can start tracking down the cause or source of an odor in one or more of several ways:

  1. 8-STEP SMELL PATCH TEST to FIND ODOR SOURCE - given below on this page: a procedure for testing specific surfaces or items to see if an odor source of if they have absorbed and are re-emitting an odor
  2. ODOR DIAGNOSIS SIX STEPS - take an orderly approach to odor source tracking in a building
  3. ODOR DIAGNOSIS CHECKLIST - an easy checklist of types of materials or items or surfaces to examine or test as possible odor sources
  4. ODORS GASES SMELLS, DIAGNOSIS & CURE - topic home, a catalog of places to look when tracking down an odor source

Using Ozone to Get Rid of Skunk or Mold Smells?

This quote from a reader's email pretty well sums up what happens if you overdo it when using an ozone generator indoors to try to "kill off" odors:

It's a long story, but I used a high powered ozone generator in our house, to get rid of skunk smell. Now I can't get rid of the left over nitric oxide, or whatever odor or gases, that linger in our house. I have been leaving the windows open every day, with running the heat on high (85 degrees) at night, to try to force off-gas the odors/gases.

We have investigated a number of cases of misapplication of ozone generating machines both to "kill mold" (no good, you're leaving toxic or allergenic particles, and you haven't corrected the reason for mold growth in the first place). We have also investigated several cases of excessive ozone-use to try to remove odors from buildings, including fire or fireplace smells, mold smells, pet or animal smells, skunk odors, smoking odors, etc.

Using an Ozone Generator Has Left a Smell in our Home - How do I Get Rid of It?

If you have aired out the building and days or more have passed and you still smell a "new" chemical or plastic or other odor that was not there before you tried using your ozone generator, you'll need to determine just what materials were oxidized by the high levels of ozone in the building.

It's been our experience that once you identify and dispose of the new-smelly material you'll probably be fine. Here are some examples of material we've found giving off horrible smells after misuse of an ozone generator. (Misuse means using the ozone generator to try to kill mold, or running an ozone generator too long at too high a setting in too small a space - overdoing it).

Try this 8-Step Smell Capture Patch Test to Pin Down a Specific Indoor Odor Source

Smell test setup on carpeting (C) Daniel Friedman

Our friend Jeff May suggested this procedure for pinning down a specific odor test in buildings - it has worked remarkably well for us where ozone had caused an indoor smell that could not be tracked down.

Our photo (left) shows the supplies you need as well as a test set up on the surface of wall to wall carpeting. We have added to, elaborated, and provided details of just how this smell patch test works - below.

  1. Purchase these indoor odor track-down supplies if you don't already have them
  1. Close up the building - windows, and doors

...

Smell test setup (C) Daniel Friedman ... Smell test setup (C) Daniel Friedman

  1. Prepare and apply odor collecting test patches on the surface of each suspected material such as carpeting, carpet padding wall surfaces, trim surfaces, furniture surfaces

Odor test patch on wall surface (C) Daniel Friedman

  1. Prepare and apply additional odor-collecting test patches on all other building surfaces to be tested as an odor source. Typically these include:
  1. Prepare additional control test patches (optional) - we apply multiple samples to the same surface as a test control described below

  2. Wait 24 hours or longer - you are allowing odors and gases under the paper towel to impregnate and be absorbed into the paper towel.

    Do not disturb the foil covering the paper towel during this time. The foil covering assures that what's being absorbed into the paper towel is emanating just from the surface being tested. The aluminum foil will also be used to quickly wrap and trap gases in the odor-filled paper towel at the end of the test period.
  3. Station your test subject person outdoors in fresh air out of the wind - select someone with a good sense of smell, or best, the person who has already complained of a specific odor in the building.

    See also ODOR SENSITIVITIY VARIES by PERSON

    This outdoor stationing of the person who is to perform the "sniff test" is very important because people who are exposed to a smell for a period of time tend to lose their ability to detect that odor. Actually some odor or chemical exposures can increase sensitivity (Rabin 1986) while in many if not most cases odor sensitivity diminishes (Dalton 1996, Zufall 1997).

    Bottom line: the "sniffer" person selected to detect the building odor whose source is being sought should be someone who already reports being familiar with the odor but who has been stationed in fresh air so as not to be de-sensitized to the smell.

    (Details are atReferences or Citations .)
Test patch being removed (C) Daniel Friedman Test patch being removed (C) Daniel Friedman
  1. Test each smell patch as follows:
Smell test container opened for sniffing (C) Daniel Friedman ... Smell test last step (C) Daniel Friedman
  1. Test your control smell patches as follows:

If a smell test is definitive, the test person will usually report very accurately which patches are from a given smell or surface area.

We have had very good results with this procedure when used to narrow down odor sources in an ozone-treated building, and we had up to 95% repeatability when we used additional smell test patches.

What Does the Odor & Smell Patch Test Kit Do or Not Do for You?

This is not a scientific test to capable of identifying the actual chemical constituents of an odor, rather it's a means of odor source location - costing almost nothing compared with paying for an air sample collection and spectrographic analysis.

Once we know the source of a smell or odor, it may be that the simplest, most-economical approach is to remove the off-gassing material or product itself.

There are indeed more technical air test methods used by industrial hygienists who collect one or more air samples in a vacuum container and send that to a lab for characterization, or who may use specific instruments designed to detect the level of specific gases or classes of gases. We will give some examples of these just below.

There are widely-marketed "air tests" sold by a number of companies testing for specific classes of gases such as "VOCs", formaldehyde, or "tobacco" - in my OPINION not something that should be a first step as the number of possible pollutants and even pollutant classes is so great, and as there is no simple single "test" that covers the spectrum.

One should note this concern about "air testing" for odors: even if we knew what chemical soup was in the air that may not be sufficiently diagnostic and it certainly won't be prescriptive - giving a course of action. To take action we need to know:

Resources for Odor & Gas Detection

 




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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 2021-02-06 by (mod) - how to do the patch test for ozone smells

KJ

The step by step procedure for performing a "smell patch test" is given in detail on the page above.

See the article header titled

Try this 8-Step Smell Capture Patch Test to Pin Down a Specific Indoor Odor Source


Watch out: This test is not specific to "ozone smells" nor any other specific odor. Furthermore, ozone is so highly volatile that you will not detect it many hours after ozone generating equipment has been turned off and removed. Instead, what may remain are odors from oxidized materials if the ozone treatment over-dosed the building.

The odor test above on this page allows the detection of any unusual or un-expected smell emanated from any building surface to which a clean folded paper towel can be left sealed for a time, then removed and sniffed.

The purpose is to track down an odor described as "a smell in this area" or "an odor in this room" to a surface from which the odor appears to emanate most-strongly.

Vnegar nor any other type of carpet cleaning will not remove an odor from carpeting that was oxidized by over-dosing with ozone. You'll need to replace the carpet and its padding.

On 2021-02-06 by KJK

I cannot find how to do the patch test for ozone smells to detect the source. The links in your information do not lead to how to do the test. Please help me. We ran an ozone machine 2 years ago in my basement and it still has a smell. I think it reacted to the carpet. Will a vinegar carpet cleaning help?

On 2021-01-30 by Anonymous

@Anonymous,
Sure. I would love the help but I’m sorry, I’m not understanding still, how to add my images. It didn’t work last time.
The important thing is, I hope someone will respond to me about the problem. I can’t stand the smell! It’s ruined my health, my mental health, and so much more

I can describe the heaters for you... the coil pieces are packed full of glued dust, debris, will not vacuum out, has been there over 40 years, from bedridden man who was in here all that time and also smoked a lot. I was told hazmat had to come after he died. Prob was dead in here. Neighbors said walls were all brown, they had to cover their nose and mouth the times they came in to help him because he was left alone. I’m sure he spilled urine bottles and food, drinks, for years and years. There’s brown tarry stuff where walls meet under heaters.

I’ve read about emergency first responders and they understand the smell. I feel for them but they can leave those places. I have had to LIVE IN IT for years because my Housing place refused to fix it. I’d like to know how to determine what something like this can do to ones health and if I’m in danger if I try cleaning it again?

So, sure.. if you think it helps to tell me how to add the photos, I’m happy to copy my text and try reposting with adding pics again. But they wouldn’t add the first time. Maybe because I’m on an iPad?
Thank you so much!! It’s a slight relief to see that someone saw my post at all!
Thank you!! Let me know. Signed, Last Nerve!

On 2021-01-08 by (mod) - ask us if you want a comment edited or deleted or just post a corrected version and we'll delete the old one

So sorry Last but you can't directly edit your prior post; however you can copy and paste the text into a new comment, then edit it before clicking the "Comment" button; I can then delete your prior or old pre-edit post.

Or you can just ask me to fix and re-post for you.

On 2021-01-08 by Last nerve

Debris and possible mold (C) InspectApedia.com@Last nerve!,
Sorry for the typos. How can I go back and edit? Thanks. Last nerve.

Dear sirs, your site has been the only real help I’ve ever found... ways to find and prove odors! Thank you! But I’m still suffering terribly. Unfortunately I lost my home from 2008 recession and ended up in Housing in 2017. I noticed slight urine smell before moving in but was ridiculed into feeling silly for saying it.

(Like, beggars can’t be choosers) First winter as a tenant I kept smelling horrible smell driving me crazy! Long story short, I found the source. Neighbors & other Housing staff confided that previous tenant was bedridden here for 35 years. Walls were brown, smell so bad it permeated thru walls to other duplex & anyone coming in had to cover face. Housing never repainted or held tenant to any clean standard but rather waited until he passed away, (prob in the unit too ?)

Source.. heater coils, specifically thousands of metal squares that are around heating pipes (forced hot water) are caked with debris that does NOT vacuum out & can’t pick out.

Brown tarry substance along floors where walls meet, All old heater pieces, which there are many, are also soiled & rusted. Walls are starting to brown again too. I’lol do patch test to see if smell still coming thru paint on walls, etc.

We had small weird fries for years and occasionally still see them. ? Housing has again ridiculed me, accusing me of just wanting a new place, denying everything. Problem in living smell is, when heaters come on, that’s when it’s at its worst! T

hey’d need to spend a while in here as the smell creeps up, but once it does, it’s on my whole face and even taste. This is my 4th winter & I am desperate, on my last nerve. My life is over in this place but being their own boss, they don’t care.

Health Dept it’s not their lane. I tied going above Housing but they retaliate. Please, is ther any help any where? Pray for me please. Not sure how to add more than 1 photo. Hope this gets to you.

On 2020-10-20 by Grace

Thank you for your articles. I am stumped. We recently added some leveling concrete in our basement and caused some cracks with a sealant however that was two months ago. Since that time we have had a sweet smell in a room not directly above. I can’t tell if this is coincidence or something else going on.

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

friedman (mod)

Ron, try the page top EXPERTS DIRECTORY

On 2020-03-06 by Ron

Who do I contact to come find a smell my commercial building? We've been looking for weeks and can not pin point it.


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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 SMELL PATCH TEST to FIND ODOR SOURCE FAQs - questions and answers posted originally on this page

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


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