Cleaning methods sprout from regs

There have been two recent developments about which you should know. They are the U.S. EPA's decision to exempt tertiary-butyl acetate from VOC regulations, and some related decisions and a recent scientific paper suggesting that removal of air (degassing) from water may render it more suitable to dissolve some organic materials without use of surfactants. On November 18, 2004, the Environmental Protection Agency (EPA) issued a final rule stating that t-butyl acetate (t-BAC) should no longer be controlled as a volatile organic compound (VOC) under the Clean Air Act (CAA). Yet, if your work is done outside of the U.S., this reclassification has no meaning to you. In Europe and Japan, VOC-exempt solvents are determined by another and quite different classification scheme. This decision wasn't hasty. The manufacturer's petition for exemption was filed late in the past decade. Since 1977, U.S. EPA has removed 48 specific compounds or classes of compounds from the list of VOCs that contribute to smog formation. The U.S. EPA is excluding t-BAC as a VOC because scientific evidence shows it is "negligibly reactive," meaning it contributes little to the formation of smog. The definition of negligible reactivity means that the solvent in question doesn't react with UV radiation at a rate greater than ethane (the benchmark). The U.S. VOC classification system is binary. All organic compounds are VOCs by definition of the CAA-unless exempted by the evaluation process conducted for t-BAC. The exemption process involves review of all submitted scientific data and con- Table is Propertu sideration of all public comments before making the final decision.