An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »


Guidance: Disclosing Confidential Data to PRPs and Contractors

Transmittal memorandum and the January 5, 1993 Federal Register notice announcing interim regulations and request for comment on Disclosure of Confidential Data to Authorized Representatives of the United States and Potentially Responsible Parties (PRPs).  58 Fed.Reg. 458 (1/5/1993). Transmittal memo issued 1/8/1993.

The interim rule updates statutory references and corrects erroneous citations to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commoly referred to as Superfund) and other environmental statutes. The interim rule is effective January 5, 1993.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.