33 CFR § 151.19 - International Oil Pollution Prevention (IOPP) Certificates.
(a) Each U.S. oil tanker of 150 gross tons and above and each other U.S. ship of 400 gross tons and above; that engages in voyages to ports or off-shore terminals under the jurisdiction of other parties to MARPOL 73/78 must have on board a valid International Oil Pollution Prevention (IOPP) Certificate.
(b) Each oil tanker of 150 gross tons and above and each other ship of 400 gross tons and above, operated under the authority of a country other than the United States that is party to MARPOL 73/78, must have on board a valid IOPP Certificate.
(d) The Supplement to the IOPP Certificate is a part of the IOPP Certificate and must remain attached to that Certificate. If the Supplement to the Certificate is changed, a new IOPP Certificate will be required.
(e) The IOPP Certificate for each inspected or uninspected ship is valid for a maximum period of 5 years from the date of issue, except as follows:
(1) A Certificate ceases to be valid if significant alterations have taken place in the construction, equipment, fittings, or arrangements required by the pollution prevention requirements of parts 155 or 157 of this chapter without the approval of the COTP or the OCMI.
(2) A Certificate ceases to be valid if intermediate surveys as required by § 151.17 of this part are not carried out.