Illinois Environmental Protection Agency (IEPA) submitted a request to the United Stated Environmental Protection Agency (USEPA) on July 3, 2013 to update the definition of Volatile Organic Material (VOM) [also known as Volatile Organic Compound (VOC)] by revising the Illinois State Implementation Plan (SIP). The request was to add trans-1, 3, 3, 3 - Tetra-Flouropropene (HFO-1234ze) to the list of excluded compounds which do not qualify as VOM. HFO-1234ze was removed from the definition of VOM in USEPA’s June 2012 rulemaking due to their negligible photochemical reactivity and contribution to tropospheric ozone. The USEPA approved the request to revise the Illinois SIP and has published the rulemaking as a direct action rule which is effective January 27, 2014 (see the Federal Register). However, this is assuming that no adverse comments are received before the end of comment period (i.e., December 26, 2013).