TSCA Chemical Substances; Unique Identifier Assignment and Application Policy; Notice of Availability

As amended in 2016, the Toxic Substances Control Act (TSCA) requires EPA to develop a system to assign a unique identifier (UID) whenever it approves a confidential business information (CBI) claim for the specific chemical identity of a chemical substance, to apply this UID to other information concerning the same chemical substance, and to ensure that any non-confidential information received by the Agency identifies the chemical substance using the UID while the specific chemical identity of the chemical substance is protected from disclosure. EPA previously requested comment on several approaches for assigning and applying UIDs. EPA has determined that it will use a numerical identifier that incorporates the year the CBI claim was asserted, and will apply this UID to non-confidential information related to the chemical substance, except where the Agency's act of applying the UID would itself disclose to the public the confidential specific chemical identity that the UID was assigned to protect.