Photograph of a Drager hand pump used to measure carbon dioxide levels in the environment. Toxic Gas & Odor Testing FAQs
Questions & answers about Toxic Gas Exposure Screenining Tests

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Toxic Gas Detection & Test Questions & Answers:

Frequently asked questions about testing & detection of toxic, harmful, or obnoxious gases & odors in & around buildings.

This article series discusses gas toxicity levels and gas testing procedures we use in field IAQ and environmental health investigations for a range of indoor gases which may be produced by building product outgassing, gas appliance leaks, plumbing and septic systems, mold and mold related volatile organic compounds MVOCs which people report as a "moldy smell", mechanical systems such as heating system-produced carbon monoxide or flue gases, fire damage, or contamination from nearby industrial, beauty parlor, dry cleaning, or other activities which often produce noxious or toxic odors and gases.

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Toxic Gas Test FAQs

Question: report on inadequate indoor gas testing, deaths, illnesse, worries about competent gas testing

My wife and I were exposed to carbon monoxide (and I'm assuming other combustible gases) for well over a year without knowing. We lived on a ground floor of an apartment and holes were drilled through the floor for plumbing and elec. but were never covered. They insurance company had Pinchin Engineering do a test on the place. and we were shown a basic 1 page sheet of CO and CO2 levels both in and around the house.

The readings from our detector that we finally bought a year later were at times almost 300. there readings were 20.

however the CO2 levels were 859.

Does this mean that combustion was happening because of both the readings and if so wouldn't tests be done for other combustible gases that may be present?

We lost a baby, dog died 2 years later, heart and kidney failure. wife has heart and joint issues. and I have a list as well. They settled out of court for $300Gs but I feel like we didn't receive ALL the disclosure from the air quality test. - Matt 11/30/11



Of course we are so sorry about the tragic losses you described, and I understand the tragedy of losing a child. When we suffer a tragic loss it is so difficult to endure that the look for a cause and blame is understandable, though sometimes we can be led astray in such a search.

In attempting to relate an illness or fatality to a building or environmental condition, a good place to start is with the physicians involved - ask about possible relationships between the illness or death and environmental factors.

About varying gas levels in buildings, our field experience confirms that small changes in a building (a window open or shut, or a door, or a bird building a nest in a chimney, or seasonal sooting in an oil fired appliance) and similar events can make an enormous difference in the measured result of indoor gases, airborne mold, other contaminants. For that reason, it is no surprise that a year later an individual measurement of gases indoors might find a very different level.

Only if the source of an indoor hazard can be clearly traced to a condition that was present, recogniziable by general home inspection standards and procedures, and visible at the time of the original inspection would one suspect the original inspector or test company of negligence.

Question: naphthalene gas has permeated carpeting, clothing, drywall

(June 12, 2015) Cragi said:
I think I may have some naphthalene gas that has permeated carpeting, clothing and maybe even some drywall. Where can I get some testing supplies to see if there is some danger for that.



I suggest starting with a consult with your doctor who might order a blood test.

NPIC notes that "Methods also exist for detecting naphthalene and its metabolites in blood, urine, feces, breast milk, and body fat but these
tests are not routinely done in a doctor’s office."

Tests in the home for any gas or chemical, if not performed by an experienced, qualified investigator are likely to give misleading results.


Question: heating oil burner odors - shared flue problem?

(June 28, 2015) Bill said:
I have both a furnace and hot water heater sharing a damper and chimney. I get a oil-type odor when either comes on. The damper has no adjustment capability. If I put a sheet of paper over the damper, it is not sucked toward the damper. I shaving both units sharing a damper a problem?

Reply: yes

Yes it's a problem.


Question: Testing burial vaults & mausoleums for lead & gases

(Dec 9, 2015) Jeremy Tilley said:
We have been asked to repair and rebuild above ground burial vaults/mausoleums which have become dangerously unstable. we need some advice with regards to how or who should test inside these vaults for lead contamination and noxious gases. Preferably we would like an expert to provide the proper tests.


I suggest looking for a local Industrial Hygienist who is familiar with lead testing and gas testing.


Question: smells traced to soon-to-be Ex Husband

(Dec 14, 2015) Carol said:

I need help!! My soon to be ex lives in a basement apartment directly under me on the first floor and I there seems to be a sweet smell oddly from only one heat zone via my baseboard heat which is where I spend most of my time. I have been experiencing various symptoms some of which are nausea, light headed, eye slightly burning,odd taste in mouth.

I have called the fire dept but their equipment shows nothing. I am waiting for toxicology blood work results and called various agencies including air quality via NYS Environmental but he cannot come here for 30 days. here is the most important part....when I confronted my ex and asked what the smell was that is only in one area upstairs which is one of 5 heat zones, his response was.....Are you accusing me of using a poisonous, toxic gas to make you sick?

OMG! What could he be doing that could direct a smell to one area?? If you're not sure, who would I call to come to my house top check for toxic gas??


I'm speechless.

Question: odor after shower was removed

(Dec 20, 2015) Anonymous said:
My husband recently took out a shower that was leaking and now there is a older very sharp not mildewy but almost toxic smell does anybody have any ideas as to what it would be


It's tough to guess at an odor from a brief e-text; Look at what got wet; look for mold. Look for drain line leaks.


Question: incinerator dust fumes

(Jan 6, 2016) Elizabeth said:
Hi, I have been dealing with incinerator dust fumes I've somehow picked up on my clothing over 3 months ago and it has traveled all over my apartment and is now in my refrigerator. How do I safely remove this noxious, toxic gas and still keep all of my food?



Question: non-fuel but gas smells from boat

(May 2, 2016) Bob said:
I have a boat with a gas type smell (not gasoline) coming from an area in the boat that is not easily accessed...The gas / smell is heavy (strongest closed to the floor) and sorta takes your breath away if you in hale deeply ...This is very frustrating trying to get to the source and ultimately a solution..Any help ideas much appreciated...



My dad sold a boat on the Rappahannock River in the 1950's - warning the buyer to vent everything before starting the engine. The buyer ignored him and blew up the boat. So please be careful. Also see LIGHTNING STRIKES SMALL BOAT -

I can't guess what you're smelling: perhaps a dead animal, or bilge water. See if you can borrow a borescope to take a closer look.

Look for bilgewater, fiberglass or plastic odors, etc.

(May 2, 2016) Bob said:
Thanks ....
The smell is definitely not animal ( I know what that is - not petroleum.
I am thinking mold/left over bilge water. That said, and say that one or the other is the problem.
What are solutions you could recommend ? Your help much appreciated.

Mod said: you need to get access to the area and at the very least, clean it of bilge water.

Question: fumes from hair salon

(June 21, 2016) D said:
I have been renting a small space (782 sq ft) for a business I own for the last 16 years. We have a hair saloon on one side of us and every once in awhile we would get fumes from the perms or nails. About 6 months ago the landlord brought in another hair saloon (long story why we have two in same plaza) but every since the second hair salon came in my little store reeks of perms/nails ect. It can get so strong that my eyes are constantly red and I have headaches. My customers are complaining. I have talked to the management and so far nothing has happened. Can you tell me how and if the fumes are dangerous and if there are a test I can perform to prove to management something needs to be done. thanks D. S.


(mod) said:
I can't assess the hazard level of gas exposure from an e-text, D, but generally if you and your customers are complaining it's pretty evident that there's at the very least an irritating level of exposure that could be harmful as well. I don't think that an amateur DIY gas level test would be credible; nor is there one single economical "test" that screens for all harmful gases. You'd need help from an industrial hygienist who can tell you which ought to be the target gases for testing (such as formaldehyde), how to measure under controlled conditions, and how to compare a measurement to an occupational exposure standard.

D said:
Thank you for your input. I'm at my wits in, maybe its time to look for a new space for my business.

(mod) said:
You could try giving your health department a call.

Or, though I'm not a ... lawyer, but your attorney might take a look at your lease; normally a landlord isn't required to do much, but "safe" and "habitable" and maybe "free from noxious odors" might be allowed for in tenant's rights.

Question: odors from fireplace when gas fired water heater is operating

(July 12, 2016) Stan M said:
I have a old house built in 1960. I replaced furnace , gas. I still have a older hot water heater vented at the chimney. When my air is circulating I smell a slight gas from the fireplace. Is their a tool I can use to detect gas. Is it posable that gases are coming from fireplace? I'm wondering if it's burning gas from the hot wate heater. Wouldn't it be vented to the chimney and could you see the metal vent on top of chimney. I'm not sure how they did back in the 60s .


Yes Stan, most home inspectors use a simple, highly-sensitive combustible gas detector - search InspectApedia for GAS DETECTION INSTRUMENTS to see details about the TIF8800 and other devices.

Watch out: there could be serious safety concerns at stake based on what you describe. I certainly would consider turning off gas supply and not using the fireplace until this condition is examined by an expert.



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