Strong Chemical Smell

Well you probably used exterior grade sealer....It will be off-gassing for a while, open the doors and windows and get some big fans....

Thompson's sealer

A uvc air purifier will help remove the odors....I would use one of these for about every 300sqft....

Went to your link. I took a snip of the ingredients:

Only 16% of that list would only remotely be called waxes. It seems to me that you would know that, having displayed a wide knowledge of coatings/paints/adhesives/etc. over the years.

See #11

Contractor grade plywood is of the lowest quality.

I don't believe that the waxes are the issue.

Fact is, no one here really knows.

MSDS's are notoriously secretive in their information so as to preserve the "competitive" edge (trade secrets) of the formula. Also to reduce the fear of toxicity of the hazardous ingredients.

Current government meddling in hazardous materials/environmental pollutants deregulation, etc. will only make this much worse!

Any threat was when the application was made 2 months ago, it's dry now....A good airing out once a day until the odor is no longer detectable, should alleviate any adverse reactions....A working exposure of 8 hrs a day is allowed by OSHA....

http://www.homedepot.com/catalog/pdfImages/6e/6e1ac4ce-1868-4d5c-9531-0917c655d15d.pdf

I have noticed that once these products get wet the odor decreases, so you might try mopping the floors...If the odor persists you may need an additional coat of interior grade sealer...

I think you are correct in your assessment that UV will be worthless in this case.

Install some plug-in heaters, and raise the room temp about 20 °F above the normal house temperature, and remember to close off the supply and return air ducts. After a few hours, ventilate the air in the room to the outdoors any way possible, and turn the room air over several times before going back to normal. The odor should be less.

..."UV light itself can not destroy VOC but UV is used as a part of a process called Photocatalytic Oxidation which can reduce or virtually eliminate VOCs from the indoor air. In the Photocatalytic Oxidation process VOC are trapped by a photocatalyst - most often titanium dioxide (TiO2) - which is activated by high intensity UV light. The harmful VOC are oxidized and turned into water and carbon dioxide."...

http://www.americanairandwater.com/uv-facts/air-pollution.htm

..." UV is used as a part of a process called Photocatalytic Oxidation which can reduce or virtually eliminate VOCs from the indoor air."...

"

What Are UV Air Sanitizers?

Simply put, UV Air Sanitizers utilize UV-C, which is part of the ultraviolet light spectrum that is filtered out by the earth’s atmosphere, to kill airborne germs. The goal is to reduce the actual growth or development of microbiological organisms such as fungi, bacteria, or viruses.

How Do UV Sanitizers Work?

UV-C light destroys the DNA of germs eliminating their ability to reproduce. Titanium Dioxide enhances killing efficiency and odor elimination."

https://www.amazon.com/GermGuardian-GG1100W-Pluggable-Sanitizer-Deodorizer/dp/B00OLBR0LG/ref=sr_1_7?s=home-garden&ie=UTF8&qid=1501716346&sr=1-7&keywords=uv%2Bair%2Bpurifier&th=1

I have 4 of these, they work great at eliminating any odors and are really fast, I'm talking a matter of minutes fast....

Agree with the others - Incorrect product for the application.

Something not yet mentioned is the solvents in the Thompson's have and may still be reacting with the (likely) urea formaldehyde resin used in laminating the plywood.

Let's hope there isn't a hypergolic combination in there somewhere.

Nonsense, Thompson's makes a wood sealer...it just needs to be dried out well to remove the odor...

https://www.walmart.com/ip/Thompson-s-WaterSeal-Clear-Wood-Sealer-Clear-1-Gallon/627744537?

Come baaaaaack!

• Was the contractor-grade plywood (the top layer as you described it) unfinished?
• How long was it left to dry after the Water Seal was applied?
• What was placed over it (carpet, hardwood, tile, etc.)?

Depending on how much was applied, this could very well still be evaporating solvents.

As stated before by Lyn and verified by the MSDS, this product is not meant for indoor application. Regretfully, the authors of the MSDS chose to relegate this information to the "fine print" of the document. Perhaps you have been taken advantage of. I hope this helps.

This is the Screwfix web page. Assuming that this is the correct "Thompsons water seal".

Exactly. It's for exterior brick and concrete. It says so in the instructions for use.

Why anyone would use it on interior wood must remain a mystery to all other CR4 readers than the Original Poster.