RESEARCH ATMOSPHERICS
From its inception in 1998, this column has covered the science and regulatory actions associated with VOC (volatile organic compound) management. The reason is that these actions constrain our choices of cleaning technology.

For more than two decades, scientists have attempted to measure and model the relationship between ozone formation and emission of VOCs. The Reactivity Research Working Group (RRWG) is a consortium of air-quality scientists and policy analysts who have been evaluating management of organic pollutant emissions on the basis of their ozone-producing potential. On June 21, 2007, a credible and independent review of the RRWG’s work was published which included the statement “...future efforts can achieve considerable success if they build upon the RRWG results...” You can download the report at www.narsto.org/section.src?SID=74.

THE TIME FOR SCIENCE HAS PASSED
Despite needs expressed by legislators and the public, Federal regulatory authorities have been reluctant to base regulations on the evolving work product of thesescientists. EPA’s reasons have been two-fold:

1. There wasn’t a consensus that the science was adequately mature and nationally applicable, and
2. Users need guidance that is robust and technically secure to support long-term business decisions. For example, it is this author’s opinion that acetone wouldn’t be exempted as it was in 1994 if a petition were filed today.

The evaluation of RRWG’s work appears to be good reason for abandoningthat reluctance.

AEROSOL COATINGS (AEROSOL SPRAY PAINTS)
Five months later, November 15, 2007, the EPA proposed their first regulation upon the RRWG’s work. It established nationwide reactivity-based standards for manufacturers (not users) of aerosol coatings. Reactivity was characterized using the scale proposed by Dr. William Carter, based on the parameter called maximum incremental reactivity (MIR). The final rule was signed on December 13, 2007. You can download this rule at www.epa.gov/ttn/oarpg/t1/fr_notices/ ACRR-11-15-07.pdf. This regulation is patterned after one promulgated by the California Air Resources Board (CARB). The proposed EPA rule containsdetails of CARB’s rule and their interests.

QUANTUM MECHANICS APPLIED TO VOC MANAGEMENT
Both rules covering aerosols limit emissions of chemicals such as acetone based on a calculation of smog formation using weighted averages of Dr. Carter’sMIR parameter. No chemical is exempt.

Yet, in solvent cleaning operations,some chemicals are considered VOCs, but some are exempt — such as acetone.

So how can a chemical be a VOC and, yet, not be a VOC? The EPA appears to have adopted this “duality” as physicists accepted that light couldbehave both as a wave and a particle:

Chemicals dispensed from aerosol spray cans that contain “coating solids” cannot be VOC exempt. Emissionswill be regulated based on weighted MIR content.

Chemicals whose mass emission rate is regulated can be VOC exempt if they qualify with adequately low MIRvalues.

The current definition of VOCs [40 CFR 51.100(s), February 7, 2007] is explained more fully at
www.epa.gov/ttn/naaqs/ozone/ozonetech/def_voc.htm. The EPA or a state would determine if a rule is mass-based or reactivity-based when it writes the rule. The rule would state how it is to be applied. The basis is the Agency’s determination of what kind of rule is best suited to protectair quality.

Apparently, if one applies VOC-exempt solvents, such as acetone, with a brush, spray bottle, or aerosol not containing “coating solids,” there is no emission of a VOC. But if one applies acetone to the same substrate from an aerosol spray can containing “coating solids,” that emissionmay be regulated.

COMING SOON
In the February C4 column, we covered methods by which the EPA produces regulations and how citizens can interact with that process. In this column, we have covered a topical regulation that affects us all and engenders controversy. In the April C4 column we will discuss future possibilities and how you shouldinteract with the EPA to affect them.

John Durkee is the author of the book Management of Industrial Cleaning Technology and Processes, published by Elsevier (ISBN 0-0804-48887).He is the author of the forthcoming book Solvent Cleaning for the 21st Century, also to be published by Elsevier, and is an independent consultant specializing in critical cleaning.You can contact him at PO Box 847, Hunt, TX 78024 or 122 Ridge Road West, Hunt, TX 78024; 830-238-7610; Fax 612-677-3170; or jdurkee@precisioncleaning.com.