The most recent meeting of the Reactivity Research Work Group, which was formed by EPA in 1998 to review and possibly update EPA’s policy for reducing emissions of VOCs, was held in July. Membership of the RRWG, although open to all, consists primarily of people from EPA and the solvents industry. The RRWG has met about twice annually to develop and fund the research believed essential to better understand the formation of ozone and fine particulate matter.
The research, part of which has been conducted at a new federally funded “smog” chamber (constructed especially for studying photochemical reactivity), is attempting to determine the photochemical reactivity of the many organic compounds released when paint and other coatings are applied. Reactivity can refer to the rate of ozone formation, the amount of ozone formed, or both.
Efforts have also been made to understand the ultimate fate of VOCs. If ozone formation characteristics of a particular VOC are slow, is the compound likely to combine with yet another atmospheric compound and form another pollutant, such as fine particulate matter, or is it more likely to condense and be washed from air by rain? If so, what then is its fate?
If the information collected on the pseudo life cycle of airborne organics is persuasive, the agency may change its VOC policy. At present, a compound is deemed a VOC only if its photochemical reactivity is greater than that of ethane.
A revised policy might result in a more complex rating scheme. A relative value would be assigned to a compound based on a laboratory demonstration of its propensity to form ozone. Were such a scale adopted, the agency might allow a high reactivity solvent to be replaced by greater quantities of a slower-reacting solvent. The presumption is that ozone concentrations would be reduced near the source of VOC emissions, yet would not increase downwind concentrations because the slower-reacting materials would be diluted by time and distance.
Tom Helms, EPA’s senior representative to the RRWG, explained that the agency expected to publish an “Advanced Notice of Proposed Rulemaking” around year’s end to inform the public that it is considering a revision of VOC control/exemption policy. The notice has been written and is currently under review within the agency.
During his presentation, Helms repeatedly urged that when the Advanced Notice is published, all parties should formally comment using a carefully constructed rationale. This writer concluded that Helms was signaling that the agency needed help in making the case to rationalize a decision that would allow increases in the mass of organic emissions allowed into the air.
Perhaps, based on long association with the remarkable advances in coatings technology, I am biased. But it seems that any action by regulating agencies that allowed increases in the mass of volatile organics into the air is a bad idea for several reasons.
Obviously, the emission of more carbon atoms would tend to increase the mass of CO2 in the atmosphere. And the nation’s reluctance to legislate CO2 reductions consistent with signatories to the Kyoto treaty has caused international tension.
Paint companies have invested enormous sums in research on low-VOC coatings during the last two decades. Remarkably, this has resulted in significant reductions in VOCs and significant improvements in performance properties.
In speaking with two technical managers of companies that have long reported improvements in product performance as a byproduct of their costly quest for compliant coatings, I learned of their mutual concern if EPA’s VOC policy is changed. They fear their investments will have been in vain; that users of paint will regress to coatings that contain more solvent (a low-cost component of most coatings) leaving a limited market for the newer, high-performance products that have limited environmental effects.
Finally, companies that wish to use higher-solvent, noncompliant paints have always had the option of using an air pollution control device.
Jim Berry is an environmental consultant and Industrial Paint & Powder Editorial Advisory Board member. E-mail him at JimBerryEC@aol.com.