Section 91.60-40 - Duration of Convention certificates(a) The following certificates are valid for a period of not more than 60 months.(1) A Cargo Ship Safety Construction Certificate.(2) A Cargo Ship Safety Equipment Certificate.(3) A Safety Management Certificate.(4) A Cargo Ship Safety Radio Certificate.(b) An Exemption certificate must not be valid for longer than the period of the certificate to which it refers.(c) A Convention certificate may be withdrawn, revoked, or suspended at any time when it is determined that the vessel is no longer in compliance with applicable requirements. (See § 2.01-70 of this chapter for procedures governing appeals.)USCG-1999-4976, 65 FR 6503 , Feb. 9, 2000