Ask the Expert Question-and-Answer Archive

by Ron Joseph

January, 2005

Exempt Solvents for Paints and Coatings

Q. Whitford manufactures nonstick & specialty (liquid-dispersion) coatings. Many are exempt under SCAQM rule 1107 as Solid-Film Lubricants, however, the solvents necessary to thin the coating & clean up the spray equipment are not, and "ordinary" solvents won't do the job. We need solvents like n-methylpyrrolidone to get the job done (to solvate the engineering polymers). Do you know of any strategies to include the thinning and clean-up solvents in the exemption? Other thoughts?

A. There are two types of "exemption". The one refers to solvents that are not counted as VOCs. In the SCAQMD regulations, such as Rule 1107 they are often referred to as "exempt" solvents or "exempt" compounds. These solvents, including acetone, methyl acetate, PCBTF, methylene chloride and others do not form smog when exposed to nitrogen oxides (NOx) and sunlight. The solvent you wish to use, NMP, is a VOC and is not an exempt solvent. It DOES form smog when exposed to NOx and sunlight. There is nothing you can do to claim an exemption for it.

The other exemption refers to permits. Coating users who use very small quantities of paints and solvents on a daily basis might be exempt from permitting. It is quite possible that you fall into that exemption, in which case your usage of NMP would not need to be permitted. In other words, you might not need to keep daily records of NMP usage, even though it IS a VOC.

You will need to study your VOC regulation and your permit regulation for this information.

If you would like me to assist you on a fee basis, I will gladly do so. Please get back to me if you need further assistance.

Best wishes,

Ron Joseph