Thanks for your interest.
As a lab, we can’t speculate on the possible health risk for the home owners or on the composition of the “trade secret.” That would be up to a risk assessor or an indoor air quality specialist.
As to how we could identify these chemicals – it’s possible that an air sample could be collected with either a sorbent tube or a Summa canister, and the resulting sample analyzed by GC/MS following either EPA TO-17 or EPA TO-15. If this is something you’d like more information about, we’d encourage you to call the lab and discuss the investigation in a bit more detail with one of our project managers.

Thanks for the wonderful article.

I was looking for a solution to my problem of masking smell of IPA when I came across your article. The staff complain about it when they use IPA as a cleaning solvent. I am going to try adding pine oil or camphor. Please suggest any other product, preferably some thing volatile which evaporates with IPA.

regards,

Ravi

In selected past odor investigation projects, our lab has seen both carbonyl sulfide and carbon disulfide related to products such as wallboard and silicone rubber. Those two components are also known low level artifacts in tedlar bags. Carbonyl sulfide can also be seen in propane and other natural gas products, since it is formed via hydrolysis in the presence of hydrogen sulfide (rotten egg smell) and carbon dioxide; however, if the source of these contaminants were from some type of natural gas/propane, I would expect to also see other natural gas odorants present as well (e.g. methyl mercaptan, tetrahydrothiophene).

There is always the possibilty of chemical interaction between constituents resulting in compounds of unknown odors. Trying to characterize the odor of the new compound would be challenging. In most cases our sweep of methods can isolate those compounds that have created the odor. I agree that common compounds such as ammonia and H2S can be easily identified by their distinct smell but in the presence of hydrocarbons it can mask the odor readily. Our methods are very specific to those class of compounds and can identify the compounds through the background. Hope this helps.

I think it will be easy to tell what compound that caused the odour, if the odour just caused by common gas specifies. Example: If easy to distinguish how is the ammonia & H2S smell like.
But if we have the odourous air sample that caused by VOC. Even can use GC-MS(screening) to analyse the sample, but is ready hard to identify which exact compounds that resposible for the odour.

My question:
1) Is they any possibility that the various VOC will react with each other and convert to another kind of VOC and make the new odor/smell that not so easy to be recognised.
That mean : If we have 10 ppm IPA and 20ppm butyl acetate encounter in the air . What would be the smell like? Will be IPA smell like, butyl acetate smell like or IPA + Butyl acetate smell.

Rgds
Johnson

ASTM International E679-91″Standard Practice for the Determination of Odor and Taste Thresholds by a Forced-Choice Ascending Concentration Series Method of Limits”

ASTM International E544-99 “Standard Practice for Referencing Suprathreshold Odor intensity“

EN 13725:2003 “Air Quality – Determination of Odor Thresholds by Dynamic Dilution Olfactometry”

Sincerely
Mitra Ramlakhan
Environmental Engineer

Steve