Ask the Expert Question-and-Answer Archive

by Ron Joseph

March, 2007

What is VOC?

Q: What do the initials V.O.C. actually stand for? And, thank you very much for your time and expertise.

A: VOC stands for "volatile organic compounds". There are the solvents and other compounds that evaporate into the air and contribute to the formation of smog (ozone).

Typical VOCs include the solvents in paints, adhesives and inks. Gasoline is 100% VOC, as is BBQ lighter fluid, the alcohol that is emitted from bakeries, and many more sources.

Water is not organic and although it evaporates into the air, it is not a VOC.

Some solvents, such as acetone, methylene chloride (in paint stripper), Freons (such as are used as refrigerants) and other fluorinated/chlorinated compounds are volatile organic compounds, however, they do not contribute to smog in any significant manner. Therefore, although they are volatile organic compounds, the EPA deems them to be exempt from the "VOC" classification. In other words, air pollution regulations that limit the use of "VOCs" exempt those compounds that have a negligible effect on the formation of smog.

I know that this is confusing, but back in the 1970s when the EPA regulations were being written, the distinction between "VOC" (smog formers) and volatile organic compounds that do not significantly contribute in to smog, was not fully appreciated.

Regards,

Ron Joseph