46 C.F.R. § 148.3
Definitions.
Cite as 46 C.F.R. § 148.3 (2026)
As used in this part—
A-60 class division
means a division as defined in § 32.57-5 of this chapter.
Adjacent space
means any enclosed space on a vessel, such as a cargo hold, cargo compartment, accommodation space, working space, storeroom, passageway, or tunnel, that shares a common bulkhead or deck with a hatch, door, scuttle, cable fitting or other penetration, with a cargo hold or compartment containing a material listed in Table 148.10 of this part.
Away from
means a horizontal separation of at least 3 meters (10 feet) projected vertically is maintained between incompatible materials carried in the same hold or on deck.
Bulk
applies to any solid material, consisting of a combination of particles, granules, or any larger pieces of material generally uniform in composition, that is loaded directly into the cargo spaces of a vessel without any intermediate form of containment.
Bulk Cargo Shipping Name
or
BCSN
identifies a bulk solid material during transport by sea. When a cargo is listed in this Part, the BCSN of the cargo is identified by Roman type and is listed in Column 1 of Table 148.10 of this part. When the cargo is a hazardous material, as defined in 49 CFR part 173, the proper shipping name of that material is the BCSN.
Cold-molded briquettes
are briquettes of direct reduced iron (DRI) that have been molded at a temperature of under 650 °C (1,202 °F) or that have a density of under 5.0 g/cm
3
;.
Commandant (CG-ENG-5)
means the Chief, Hazardous Materials Division of the Office of Design and Engineering Systems. The mailing address is: Commandant (CG-ENG-5), Attn: Hazardous Materials Division, U.S. Coast Guard Stop 7509, 2703 Martin Luther King Jr. Avenue SE., Washington, DC 20593-7509; telephone 202-372-1420 or email
hazmatstandards@uscg.mil.
Compartment
means any space on a vessel that is enclosed by the vessel's decks and its sides or permanent steel bulkheads.
Competent authority
means a national agency responsible under its national law for the control or regulation of a particular aspect of the transportation of hazardous materials.
Confined space
means a cargo hold containing a material listed in Table 148.10 of this part or an adjacent space not designed for human occupancy.
Domestic voyage
means transportation between places within the United States other than through a foreign country.
Hazard class
means the category of hazard assigned to a material under this part and 49 CFR parts 171 through 173.
Hazard Class Definitions
Hazard Classes Used in This Part Are Defined in the Following Sections of Title 49
Class No.
Division No. (if any)
Description
Reference
(49 CFR)
1
1.1, 1.2, 1.3, 1.4, 1.5, 1.6
Explosives
§ 173.50
2
2.1, 2.2, 2.3
Flammable Gas, Non-Flammable Compressed Gas, Poisonous Gas
§ 173.115
3
Flammable and Combustible Liquid
§ 173.120
4
4.1, 4.2, 4.3
Flammable Solid, Spontaneously Combustible Material, Dangerous When Wet Material
§ 173.124
5
5.1
Oxidizer
§ 173.127
5
5.2
Organic Peroxide
§ 173.128
6
6.1
Poisonous Materials
§ 173.132
6
6.2
Infectious Substance
§ 173.134
7
Radioactive Material
§ 173.403
8
Corrosive Material
§ 173.136
9
Miscellaneous Hazardous Material
§ 173.140
Hazardous substance
is a hazardous substance as defined in 49 CFR 171.8.
Hold
means a compartment below deck that is used exclusively for the stowage of cargo.
Hot-molded briquettes
are briquettes of DRI that have been molded at a temperature of 650 °C (1,202 °F) or higher, and that have a density of 5.0 g/cm
3
(312 lb/ft
3
) or greater.
IMSBC Code
means the English version of the “International Maritime Solid Bulk Cargoes Code” published by the International Maritime Organization (incorporated by reference, see § 148.8).
Incompatible materials
means two materials whose stowage together may result in undue hazards in the case of leakage, spillage, or other accident.
International voyage
means voyages—
(1) Between any place in the United States and any place in a foreign country;
(2) Between places in the United States through a foreign country; or
(3) Between places in one or more foreign countries through the United States.
Lower flammability limit
or
LFL
means the lowest concentration of a material or gas that will propagate a flame. The LFL is usually expressed as a percent by volume of a material or gas in air.
Master
means the officer having command of a vessel. The functions assigned to the master in this part may also be performed by a representative of the master or by a person in charge of a barge.
Material safety data sheet
or
MSDS
is as defined in 29 CFR 1910.1200.
Person in charge of a barge
means an individual designated by the owner or operator of a barge to have charge of the barge.
Potentially Dangerous Material
or
PDM
means a material that does not fall into a particular hazard class but can present a danger when carried in bulk aboard a vessel. The dangers often result from the material's tendency to self-heat or cause oxygen depletion. Materials that present a potential danger due solely to their tendency to shift in the cargo hold are not PDMs. For international shipments prepared in accordance with the IMSBC Code (incorporated by reference, see § 148.8), equivalent terminology to PDM is Material Hazardous only in Bulk (MHB).
Readily combustible material
means a material that may not be a hazardous material but that can easily ignite and support combustion. Examples are wood, straw, vegetable fibers, and products made from these materials, and coal lubricants and oils. The term does not include packaging material or dunnage.
Reportable quantity
or
RQ
means the quantity of a hazardous substance spilled or released that requires a report to the National Response Center. The specific RQs for each hazardous substance are available in 49 CFR 172.101, Appendix A.
Responsible person
means a knowledgeable person who the master of a vessel or owner or operator of a barge makes responsible for all decisions relating to his or her specific task.
Seed cake
means the residue remaining after vegetable oil has been extracted by a solvent or mechanical process from oil-bearing seeds, such as coconuts, cotton seed, peanuts, and linseed.
Shipper
means any person by whom, or in whose name, or on whose behalf, a contract of carriage of goods by sea has been concluded with a carrier; or any person by whom or in whose name, or on whose behalf, the goods are actually delivered to the carrier in relation to the contract of carriage by sea.
Shipping paper
means a shipping order, bill of lading, manifest, or other shipping document serving a similar purpose.
Stowage factor
means the volume in cubic meters of 1,000 kilograms (0.984 long tons) of a bulk solid material.
Threshold limit value
or
TLV
means the time-weighted average concentration of a material that the average worker can be exposed to over a normal eight-hour working day, day after day, without adverse effect. This is a trademark term of the American Conference of Governmental Industrial Hygienists (ACGIH).
Transported
includes the various operations associated with cargo transportation, such as loading, off-loading, handling, stowing, carrying, and conveying.
Trimming
means any leveling of a cargo within a cargo hold or compartment, either partial or total.
Tripartite agreement
means an agreement between the national administrations of the port of loading, the port of discharge, and the flag state of the vessel, on the conditions of carriage of a cargo.
Ventilation
means exchange of air from outside to inside a cargo space and includes the following types:
(1)
Continuous ventilation
means ventilation that is operating at all times. Continuous ventilation may be either natural or mechanical;
(2)
Mechanical ventilation
means power-generated ventilation;
(3)
Natural ventilation
means ventilation that is not power-generated; and
(4)
Surface ventilation
means ventilation of the space above the cargo. Surface ventilation may be either natural or mechanical.
Vessel
means a cargo ship or barge.
[75 FR 64591, Oct. 19, 2010, as amended by USCG-2013-0671, 78 FR 60154, Sept. 30, 2013]
- Cross-references to the CFR
- 148.8173.115173.120173.124173.127173.128173.132173.134173.136173.140173.403173.5029:1910.1200.32.57-549:171.8.49:172.101