Expert: Dr. Henry Boyter, Jr. - 8/2/2005

Question
Thanks. Is water based better because there are no solvents an djust VOC in it. Someone was trying to sell polyurethane with no solvent and VOC only, but I don't understand who it can be. Can there be solvents that are not VOC?

I understand that nothing is 100% but from my reading it appeared that VOCs are gases. Are other  non-VOC solvents that could potentially be in water based polyurethane gases too?

I have a MSDS and it lists only two ingidients, 5%-10% one and 1%-5% one. The rest are mentioned. The rest of chemicals are mentioned because in Regulatory Section because they are known in state of California to cause cancer, etc. I think it also said somewhere that VOC is no more than 390g per liter.


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Followup To
Question -
Thank you very much for your reply. Could I ask when is eventually?

Is it true that all VOCs will evaporate in 1 week? If not how long do I need to wait?

What about solvents? Do all of them evaporate in one week?

I have a list of some chemicals in the product I can easily get and was told is very good.

N-Methyl-2-Pyrrolidone  5%-10%
Ethylbenzene
Oxirane
Hydrazine
Benzene
Diethylene Glycol Ethyl Ether 1% - 5%

Will all of those evaporate completely and make the wood finish fairly safe if piece is ingested?

Thank you very much
Answer -
None of your questions can be answered since every situation will be different.  If you live in the Arizona desert, it will happen faster than the bogs of Louisiana.  Total offgasing may not happen for years, but the levels will get to be so low, they may only be measureable with the most sensitive equipment.  Nothing ever evaporates 100% completely.  You can't measure that.

I am not sure where you got that list of ingredients, but unless the four ingreients with no % are listed as trace or impurities, I wouldn't use it.  I have a feeling you are reading very trace impurities that companies have to list, even if they can't be measured.  Benzene is the worst, but you are exposed to it every time you pump gas as are the others.  The other two are common solvents in some household cleaners and other products.

As far as the finish, "fairly safe" has no meaning.  Only you can decide what is best for your family.  I would say that you shouldn't do this job with children in the same area at least until you can't smell the strong odors of the solvent.  The same would be true for painting, gas tank filling, laundry, etc.  You may want to go to a water based system if you are not comfortable with the normal system.

Answer
If it has VOCs more than trace amounts it has a solvent.
On the other hand, all solvents are not VOCs.  VOC is a USEPA definition.  Almost all VOCs are liquids at room temperature.

Volatile Organic Compound (VOC): Any organic compound that participates in atmospheric photochemical reactions except those designated by EPA as having negligible photochemical reactivity.

Note the definition never says anything officially about health problems, but it is implied, but then again many VOCs do not cause direct health problems.  VOCs was originally to define chemicals that contribute to smog and visible air pollution.

The things listed in California are only listed because they are present in trace amounts and are just impurities left from the manufacturing process.  I had a feeling they would be California.

Yes, water based products can have solvents in them, but they usually don't.  Only the MSDS will tell you.  In fact both of the solvents in the product you mentioned can be present in water based products, but they would be listed as VOCs.  Water based just mean water is the largest percentage solvent present.  It may be the only one, but it may not.

Don't think I can be more help at this point. You have some decisions to make.  Good luck.