The U.S. Environmental Protection Agency (EPA) has announced that, unless it receives adverse comments by the close of the comment period on August 13, 2010, it will approve revisions to the California State Implementation Plan (SIP). A SIP is an enforceable plan, developed at the state level and submitted to the EPA for approval, that explains how the state will attain and maintain National Ambient Air Quality Standards (NAAQS) set by the EPA for certain criteria pollutants. The Federal Clean Air Act (CAA) requires each state to develop and regularly update a SIP. SIPs are necessary and important. They play a key role in defining compliance with the CAA. The revisions proposed by the EPA are revisions to the Sacramento Metropolitan Air Quality Management District (SMAQMD) and South Coast Air Quality Management District (SCAQMD) portions of the California SIP. Approval of the revisions will enable California and the EPA to regulate volatile organic compound (VOC) emissions from “vanishing oils, rust inhibitors, plastic coatings, rubber coatings, glass coatings and aerospace operations.”  Information on how to submit comments on-line or by e-mail or by mail is available at Comments should contain the docket number EPA-R09-OAR-2010-0514.