Group | B | Reduction of Ozone Formation by VOCs INTRODUCTION Chapter 6 discusses the basics and details of EPAs regula- tion of VOCs in the US and the atmospheric modelingsupporting those regulations. Subchapters 6.7 through 6.9 examine various solvent types and their effects on ozone formation. Subchapter 6.11 lists one outcome of that reg- ulationdthe fty- odd solv ents anointe d as bein g VOC exempt because their emission generates negligible ozone. This appendix builds on that work, completes a multi- dimensional examination of the effect of solvent structure on ozone generation by solvent emissions in the tropo- spher e, and examines one regu lato ry appr oach to usingthat analysis. Appendix B1 desc ribes the normal chemical reactions which organic solvents undergo in the troposphere. This complicated technology is communicate d in a simplied fashion using conventional chemical nomenclature. Operation of smog chambers is also described, to show how these reactions are studied and the metrics needed for regulation are measured. Appendix B2 incl udes a unique ex amination of the use of group contribution technology (Appendix C8) to determine which solvent structures have the greatesteffects on ozone generation. The predictions of the group contribution approach and the abov e examinat ion of solvent type are coll ecte d and rationalized. The outcome is that both approaches allow recognition of which solvents should be prioritized for use in open-top machines to limit ozone generation. This outcome supports the solventsubstitution technology developed in Subchapters 6.8 and 6.9 to select cleaning solvents based on theirpotential to form ozone. 545
Chapter 6 discusses the basics and details of EPAs regula-tion
of VOCs in the US and the atmospheric modelingsupporting those
regulations. Subchapters 6.7 through 6.9examine various solvent
types and their effects on ozoneformation. Subchapter 6.11 lists
one outcome of that reg-ulationdthe fty-odd solvents anointed as
being VOCexempt because their emission generates negligible
ozone.This appendix builds on that work, completes a multi-
dimensional examination of the effect of solvent structureon
ozone generation by solvent emissions in the tropo-sphere, and
examines one regulatory approach to usingthat analysis.
Appendix B1 describes the normal chemical reactionswhich organic
solvents undergo in the troposphere.This complicated technology is
communicated in
a simplied fashion using conventional chemicalnomenclature.
Operation of smog chambers is alsodescribed, to show how these
reactions are studiedand the metrics needed for regulation are
measured.
Appendix B2 includes a unique examination of theuse of group
contribution technology (Appendix C8)to determine which solvent
structures have the greatesteffects on ozone generation.The
predictions of the group contribution approachand the above
examination of solvent type are collectedand rationalized. The
outcome is that both approachesallow recognition of which solvents
should beprioritized for use in open-top machines to limit
ozonegeneration. This outcome supports the solventsubstitution
technology developed in Subchapters6.8 and 6.9 to select cleaning
solvents based on theirpotential to form ozone.
