49 CFR 1520.19 - Destruction of SSI.
(a) DHS. Subject to the requirements of the Federal Records Act (5 U.S.C. 105), including the duty to preserve records containing documentation of a Federal agency's policies, decisions, and essential transactions, DHS destroys SSI when no longer needed to carry out the agency's function.
(b) Other covered persons -
(1) In general. A covered person must destroy SSI completely to preclude recognition or reconstruction of the information when the covered person no longer needs the SSI to carry out transportation security measures.