33 CFR 151.33: Certificates for carrying Category C oil-like NLS
Last reviewed: October 14, 2026
This section says which certificates an oceangoing ship needs before it carries a Category C oil-like NLS listed in § 151.49 in a cargo tank. The certificates depend on whether the ship is U.S. or foreign and whether a U.S. ship is on a foreign voyage.
Applies toU.S. oceangoing ships, foreign oceangoing ships operating in the navigable waters of the U.S., and U.S. oceangoing ships authorized to carry certain dangerous cargoes in bulk under 46 CFR part 98.
What it says
A U.S. oceangoing ship may not carry a Category C oil-like NLS listed in § 151.49 in a cargo tank unless it has a Certificate of Inspection endorsed to allow that NLS in that tank.
33 CFR 151.33(a)“A U.S. oceangoing ship may not carry a Category C oil-like NLS listed in § 151.49 in a cargo tank unless the ship has a Certificate of Inspection endorsed to allow the NLS to be carried in that cargo tank”
If a U.S. oceangoing ship engages in a foreign voyage, it must also have either an Attachment for NLSs to the IOPP Certificate, issued under § 151.37(a), or a Certificate of Fitness issued under 46 CFR part 153. Either one must allow the NLS in that cargo tank.
33 CFR 151.33(a)(1)“An Attachment for NLSs to the IOPP Certificate, issued under § 151.37(a), that allows the NLS to be carried in that cargo tank; or”
As the alternative to the IOPP Attachment, a U.S. oceangoing ship on a foreign voyage may have a Certificate of Fitness issued under 46 CFR part 153 that allows the NLS in that cargo tank.
33 CFR 151.33(a)(2)“A Certificate of Fitness issued under 46 CFR part 153 that allows the NLS to be carried in that cargo tank.”
A foreign oceangoing ship operating in the navigable waters of the U.S. may not carry a Category C oil-like NLS listed in § 151.49 in a cargo tank unless it has one of the two certificates described in paragraphs (b)(1) and (b)(2).
33 CFR 151.33(b)“A foreign oceangoing ship operating in the navigable waters of the U.S. may not carry a Category C oil-like NLS listed in § 151.49 in a cargo tank unless the ship has—”
A foreign oceangoing ship may meet this by holding an Attachment for NLSs to the IOPP Certificate that allows the NLS in that cargo tank, or a Certificate of Compliance issued under 46 CFR part 153 that allows it.
33 CFR 151.33(b)(2)“A Certificate of Compliance issued under 46 CFR part 153 to allow the NLS to be carried in that cargo tank.”
A U.S. oceangoing ship authorized to carry certain dangerous cargoes in bulk under 46 CFR part 98 must have a Certificate of Inspection endorsed for the NLS in that cargo tank, and on a foreign voyage also an NLS Certificate issued under § 151.37(b).
33 CFR 151.33(c)“and if the ship engages in a foreign voyage, an NLS Certificate issued under § 151.37(b) that allows the NLS to be carried in that cargo tank.”
Common questions
What certificate does a foreign ship need to carry Category C oil-like NLS in U.S. waters?
A foreign oceangoing ship operating in the navigable waters of the U.S. must have either an Attachment for NLSs to the IOPP Certificate or a Certificate of Compliance issued under 46 CFR part 153. Either one must allow the NLS in that cargo tank.
“A Certificate of Compliance issued under 46 CFR part 153 to allow the NLS to be carried in that cargo tank.”
Does a U.S. ship on a foreign voyage need more than a Certificate of Inspection to carry Category C oil-like NLS?
Yes. A U.S. oceangoing ship on a foreign voyage also needs either an IOPP Certificate Attachment for NLSs or a Certificate of Fitness issued under 46 CFR part 153.
“A Certificate of Fitness issued under 46 CFR part 153 that allows the NLS to be carried in that cargo tank.”
What certificate applies to a U.S. ship carrying dangerous cargoes in bulk under 46 CFR part 98?
It must have a Certificate of Inspection endorsed for the NLS in that cargo tank. On a foreign voyage it also needs an NLS Certificate issued under § 151.37(b).
“and if the ship engages in a foreign voyage, an NLS Certificate issued under § 151.37(b) that allows the NLS to be carried in that cargo tank.”
The text of 33 CFR 151.33
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
Certificates needed to carry Category C Oil-like NLS
(a) A U.S. oceangoing ship may not carry a Category C oil-like NLS listed in § 151.49 in a cargo tank unless the ship has a Certificate of Inspection endorsed to allow the NLS to be carried in that cargo tank, and if the ship engages in a foreign voyage—
(1) An Attachment for NLSs to the IOPP Certificate, issued under § 151.37(a), that allows the NLS to be carried in that cargo tank; or
(2) A Certificate of Fitness issued under 46 CFR part 153 that allows the NLS to be carried in that cargo tank.
(b) A foreign oceangoing ship operating in the navigable waters of the U.S. may not carry a Category C oil-like NLS listed in § 151.49 in a cargo tank unless the ship has—
(1) An Attachment for NLSs to the IOPP Certificate that allows the NLS to be carried in that cargo tank; or
(2) A Certificate of Compliance issued under 46 CFR part 153 to allow the NLS to be carried in that cargo tank.
(c) A U.S. oceangoing ship authorized to carry certain dangerous cargoes in bulk under 46 CFR part 98 may not carry a Category C oil-like NLS listed in § 151.49 in a cargo tank unless the ship has a Certificate of Inspection endorsed to allow the NLS to be carried in that cargo tank, and if the ship engages in a foreign voyage, an NLS Certificate issued under § 151.37(b) that allows the NLS to be carried in that cargo tank.
Sections it refers to
- 33 CFR 151.49
- 33 CFR 151.37
- 46 CFR part 153
- 46 CFR part 98
The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.