(a) Employees shall not possess firearms, explosives, or other dangerous weapons, as defined at 40 U.S.C. 5104(a), either openly or concealed, while on Department property or while on official duty.

(b) The prohibition of paragraph (a) of this section does not apply to the possession of authorized weapons or explosives by employees who are required to possess such authorized weapons or explosives in the performance of their official duties.