SACRAMENTO, Calif. — The California Air Resources Board (ARB) has completed an 18-month evaluation of decamethylcyclopentasiloxane (D5) silicon, the solvent used in GreenEarth. According to a letter published at its website, ARB has determined that D5 is an “acceptable drycleaning solvent alternative” to perchloroethylene, but is not eligible for the state’s grant program.
“There is probably no state in the nation with environmental standards more rigorous than those adopted in California — and the Air Resources Board is no exception,” says Tim Maxwell, president of the Kansas City-based marketer. “We are delighted that this ruling clears the air on the safety of our process and its suitability as a viable alternative to perc.”
Under ARB’s determination, GreenEarth will require no additional regulation for use by drycleaners in California. However, operators who switch to the D5-based solvent will not be eligible for grant monies under the provisions of AB 998, which offers incentives to promote the installation of replacement technologies determined to be nontoxic and non-smog-forming. So far, only wetcleaning and CO2 equipment qualify for ARB grants.
After an evaluation of the information available on D5 silicon, California’s Office of Evironmental Health Hazard Assessment (OEHHA) expressed concerns about the compund’s persistence in animal and human tissues and the environment. OEHHA also cited a lingering concern about a study in which D5 produced uterine tumors in laboratory rats exposed to the highest possible vapor concentrations of solvent.
However, ARB indicated that the responsible use of GreenEarth solvent poses no adverse health risk to drycleaning operators and “will not pose an adverse health risk to the public.” The Silicones Environmental, Health & Safety Council of North America (SEHSC) will continue to present information to the OEHHA to prove that D5 is nontoxic and deserving of grant monies.
“While we have not yet achieved eligibility for the state’s grant program, we remain confident we will achieve that status in the future as even more data becomes available,” Maxwell says. “Much more important, though, is CARB’s determination that the process does not pose a health risk, and therefore does not need to be regulated.
“The good news is that the quality of GreenEarth’s cleaning and the economics of our business model give us a strong competitive advantage with or without participation in the grant program,” Maxwell says. Based on the process’ safety, effectiveness and economic viability, “we are confident that we offer the best alternative.”