An official website of the United States government.

Due to a lapse in appropriations, EPA websites will not be regularly updated. In the event of an environmental emergency imminently threatening the safety of human life or where necessary to protect certain property, the EPA website will be updated with appropriate information. Please note that all information on the EPA website may not be up to date, and transactions and inquiries submitted to the EPA website may not be processed or responded to until appropriations are enacted.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Mercury and Air Toxics Standards

How to Comment: Proposed Revised Supplemental Finding and RTR

EPA will accept comments on the proposed rule for 60 days after publication in the Federal Register. Comments should be identified by Docket ID No. EPA-HQ-OAR-2018-0794 and may be submitted by one of the following methods.

  • Online: Go to and follow the instructions for submitting comments to EPA-HQ-OAR-2018-0794.
  • Email: Comments may be sent to Include Docket ID No. EPA-HQ-OAR-2018-0794 in the subject line of the message.
  • Mail: Environmental Protection Agency, EPA Docket Center (EPA/DC), Mail Code 28221T, Attention Docket ID No. EPA-HQ-OAR-2018-0794, 1200 Pennsylvania Avenue, NW, Washington, DC 20460.
  • Fax: Fax your comments to: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-2018-0794. 
  • Hand/Courier Delivery: EPA Docket Center, Room 3334, EPA WJC West Building, 1301 Constitution Avenue, NW, Washington, DC 20004, Attention Docket ID No. EPA-HQ-OAR-2018-0794. Such deliveries are only accepted during the Docket’s normal hours of operation, and special arrangements should be made for deliveries of boxed information.