U.S. EPA Adds New Exclusion to the Definition of Volatile Organic Compounds (VOCs)

On June 22, 2012, a notice was published informing that the U.S. EPA revised its definition of volatile organic compounds (VOCs) to exclude 1,3,3,3-tetrafluoropropene.  This exclusion will officially be effective on July 23, 2012.  What is 1,3,3,3-tetrafluoropropene?  This compound is also known as HFO-1234ze and may be used as a refrigerant, an aerosol propellant, and a blowing agent for insulating foam.  HFO-1234ze is being excluded from the list of VOCs because it has been deemed negligibly reactive.  A little fact that I found interesting in the course of reading this action is that the U.S. EPA uses the reactivity of ethane as the threshold for determining whether a compound has negligible reactivity.  Any compound that is more reactive than ethane is considered a VOC for regulatory purposes and has control requirements.  Ethane was chosen as the threshold compound based on series of smog chamber experiments.