21 CFR § 20.49 - Denial of a request for records.
(a) A denial of a request for records, in whole or in part, shall be signed by the Director, Division of Freedom of Information (or delegatee).
(b) The name and title or position of each person who participated in the denial of a request for records shall be set forth in the letter denying the request. This requirement may be met by attaching a list of such individuals to the letter.
(c) A letter denying a request for records, in whole or in part, shall state the reasons for the denial, the appropriate review official and address to which the appeal should be sent, and that an appeal must be transmitted within 90 calendar days from the date of the adverse determination, in accordance with 45 CFR 5.61. The Agency will also make a reasonable effort to include in the letter an estimate of the volume of the records denied, unless providing such an estimate would harm an interest protected by an exemption under the Freedom of Information Act. This estimate will ordinarily be provided in terms of the approximate number of pages or some other reasonable measure. This estimate will not be provided if the volume of records denied is otherwise indicated through deletions on records disclosed in part. The letter will also include contact information for the Freedom of Information Act Public Liaison and the Office of Government Information Services.