Ask the Expert Question-and-Answer Archive

by Ron Joseph

March, 2005

Definition of Exempt Solvents, (VOC)

Q. Ron, Excellent presentation in Metal Finishing this month (Feb '05) re VOC. Could I ask (1) where do you look to find the "exempt" and "non-exempt" status of a solvent.....is there a good website? (2) did the EPA Method 24 use the test method of ASTM, i.e., 1 hour drying at 105°C, as a basis for "volatiles"? Do they still use this method at all?

Thanks, and keep up the good work.

A. Thanks for the compliment.

40 CFR Part 51.100(s) "Volatile organic compounds (VOC) means any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.

(1) This includes any such organic compound other than the following, which have been determined to have negligible photochemical reactivity:
acetone
methyl acetate
methylene chloride (dichloromethane)
1,1,1-trichloroethane (methyl chloroform)
parachlorobenzotrifluoride (PCBTF)
cyclic, branched, or linear completely methylated siloxanes
(Comment: several other compounds not listed here since they are not applicable to Paints and Coatings)

(2) For purposes of determining compliance with emissions limits, VOC will be measured by the test methods in the approved State implementation plan (SIP) or 40 CFR part 60, appendix A, as applicable. Where such a method also measures compounds with negligible photochemical reactivity, these negligibility-reactive compounds may be excluded as VOC if the amount of such compounds is accurately quantified, and such exclusion is approved by the enforcement authority."

EPA

Best Wishes,

Ron Joseph