20 CFR § 375.5 - Organization and functions of the Board, delegations of authority, and lines of succession.
(a) During a national emergency, as defined in § 375.2, the respective functions and responsibilities of the Board shall be, to the extent possible, as set forth in the U.S. Government Manual, which is published annually by the Office of the Federal Register, and is available on the Internet at http://www.nara.gov/fedreg/, under Other Publications.
(b) The following delegation of authority is made to provide continuity in the event of a national emergency:
(2) In the absence or incapacity of the Chair, the authority of the Chair to act shall pass to the available successor highest on the following list:
(3) Except as may be determined otherwise by the Chair of the Board or his or her successor and as provided in §§ 375.6 and 375.7, the duties of each office head or regional director shall be discharged in his or her absence or incapacity during a national emergency by the available staff member next in line of succession. Each office head and each regional director shall designate and preposition the line of succession within his or her office or region. If no such designation has been made, such duties shall be assumed by the available subordinate who is highest in grade or, if there is more than one, in length of Board service.
(4) Emergency responsibility and authority under this section, once assumed, shall be relinquished on direction of the duly constituted higher authority acting under the provisions of paragraph (b)(2) of this section.