Tomorrow, EPA will announce in the Federal Register that it is removing 72 of the currently allowable compounds used as inert ingredients in pesticide formulations. The list of allowable inert substances is maintained by a specialized branch with the Office of Pesticide Program's Registration Division and any compound on this list may be used in a EPA-registered pesticide for non-food uses without any additional authorization. (New inert ingredients will require approval from the branch in addition to new fees for such services levied under PRIA3.)
EPA undertook an analysis that determined that these 72 compounds are no longer used in pesticide formulations and will thus be removed from the list. In order to be reinstated back on the list, a registrant would have to submit a petition "supported by data provided to and reviewed by the EPA as part of a new inert ingredient submission request." (See more info on the process here.) In addition, EPA is describing this action as "fulfilling a commitment as described in an EPA May 22, 2014 amended response to the petitioners" ... back in 2006, the Northwest Coalition for Alternatives to Pesticides and a group of State Attorney Generals petitioned EPA identified over 370 chemicals in pesticide formulations as hazardous and demanded that EPA disclose the presence of these compounds on the label. It was this group of roughly 370 chemicals that EPA analyzed to identify the current batch of 72 that is no longer used. There's more than you wanted to know on this sage here. [It should also be noted that EPA revoked the tolerance of many inerts immediately following the submittal of the petitions, citing "insufficient evidence" on file to support a safety finding. This resulted in a large industry-led effort, the Joint Inerts Task Force, to develop these data to reinstate revoked tolerances.]
The Agency's revised May 2014 response to the petitioners and the list of 72 substances will be posted to regulations.gov at docket EPA-HQ-OPP-2014-0558 in the coming days. Chances are if it is not posted by later afternoon tomorrow, you may be still able to obtain it directly from the EPA.