Extended Operational and Trade Vocabulary

IMDG Code: Classes, Divisions, Segregation, and Key UN Numbers glossary (page 2)

Terminology of the IMDG Code for dangerous goods at sea: hazard classes and divisions, key UN numbers such as aerosols UN 1950 and ammonium nitrate UN 1942, the amendment cycle adopted by IMO resolutions like MSC.501(105) and MSC.532(107), recognised classification societies, and the segregation and stowage rules governing packaged dangerous cargo.

344 defined terms.

Showing 94 on this page (page 2 of 2).

S

Stowage Category D: On deck only on cargo ships, on deck only on passenger ships meeting specified conditions.
Stowage Category E: On deck or under deck on cargo ships and prohibited on passenger ships.
Sub-risk Label Position: Subsidiary risk labels are placed adjacent to the primary risk label and do not bear the class number unless required.
Subsidiary Hazard Label: A label displayed below the primary label representing additional hazards posed by the substance, e.g., Class 6.1 toxic subsidiary on a Class 3 entry.
Sulphuric Acid Spent UN 1832: A Class 8 acid recovered from industrial processes, packing group II.
Sulphuric Acid UN 1830: A Class 8 corrosive liquid containing more than 51 per cent H2SO4, packing group II.
Surface Contamination Limit: For Class 7 packages, 4 Bq/cm2 for beta/gamma emitters and 0.4 Bq/cm2 for alpha emitters as non-fixed contamination.

T

Tank container: ISO tank container for liquids and gases.
Tank Hierarchy: Portable tank instructions T1 through T75 covering minimum design pressures, openings, and emergency relief specifications.
Technical Name: The recognised chemical name supplementing an N.O.S. PSN per special provision 274.
Temperature Control Requirements: Mandatory for Class 4.1 self-reactive Type B-F and Class 5.2 Type B-F organic peroxides above SADT minus 10 deg C threshold.
Test O.1 / O.2 / O.3: Tests in the UN Manual of Tests and Criteria used to assign Class 5.1 packing groups for solid (O.1, O.3) and liquid (O.2) oxidisers.
Tetrahydrofuran UN 2056: A Class 3 flammable liquid, packing group II, with peroxide formation risk requiring inhibitor.
Toxic by Inhalation (TIH): A subset of Class 6.1 substances classified by inhalation toxicity criteria in 2.6.2.2.4 and assigned hazard zones.
Toxic Liquid Organic NOS UN 2810: A Class 6.1 generic entry, packing group I, II, or III based on LD50 and LC50 data with technical name.
Transport Index (TI): The number expressing the maximum radiation dose rate at 1 m from the surface of a Class 7 package, divided by 0.01 mSv/h.
Trefoil Symbol: The radiation hazard symbol (three blades around a central circle) on Class 7 labels.

U

UN 1066 Nitrogen Compressed: Class 2.2 non-flammable non-toxic compressed gas.
UN 1075 Petroleum Gases Liquefied: Class 2.1 LPG mixture.
UN 1170 Ethanol or Ethanol Solution: Class 3 PG II or III depending on concentration and flashpoint.
UN 1202 Diesel Fuel: Class 3 flammable liquid PG III.
UN 1203 Motor Spirit (Gasoline): Class 3 PG II.
UN 1223 Kerosene: Class 3 PG III.
UN 1263 Paint or Paint Related Material: Class 3 PG I, II, or III based on flashpoint.
UN 1267 Petroleum Crude Oil: Class 3 PG I, II, or III based on properties.
UN 1268 Petroleum Distillates NOS: Class 3 PG I, II, or III.
UN 1547 Aniline: Class 6.1 PG II.
UN 1789 Hydrochloric Acid: Class 8 PG II or III.
UN 1791 Hypochlorite Solution: Class 8 PG II or III.
UN 1805 Phosphoric Acid Solution: Class 8 PG III.
UN 1824 Sodium Hydroxide Solution: Class 8 PG II or III.
UN 1830 Sulphuric Acid: Class 8 PG II.
UN 1888 Chloroform: Class 6.1 PG III.
UN 1942 Ammonium Nitrate: Class 5.1 PG III with <0.2 per cent combustible.
UN 1950 Aerosols: Class 2 with division based on contents (2.1, 2.2, or 2.3).
UN 1956 Compressed Gas NOS: Class 2.2.
UN 1965 Hydrocarbon Gas Mixture Liquefied NOS: Class 2.1 LPG mixture.
UN 1972 Methane Refrigerated Liquid (LNG): Class 2.1.
UN 1977 Nitrogen Refrigerated Liquid: Class 2.2 cryogenic.
UN 1978 Propane: Class 2.1 flammable liquefied gas.
UN 1986 Alcohols Flammable Toxic NOS: Class 3 with subsidiary risk 6.1, PG I, II, or III.
UN 1993 Flammable Liquid NOS: Class 3 generic entry.
UN 2014 Hydrogen Peroxide Aqueous Solution 20-60 Per Cent: Class 5.1 with subsidiary 8, PG II.
UN 2031 Nitric Acid: Class 8 with subsidiary 5.1 if greater than 65 per cent, PG I or II.
UN 2056 Tetrahydrofuran: Class 3 PG II.
UN 2735 Amines Liquid Corrosive NOS: Class 8 PG I, II, or III.
UN 2810 Toxic Liquid Organic NOS: Class 6.1 PG I, II, or III.
UN 2814 Infectious Substance Affecting Humans: Class 6.2 Category A.
UN 2900 Infectious Substance Affecting Animals Only: Class 6.2 Category A.
UN 3077 Environmentally Hazardous Substance Solid NOS: Class 9 marine pollutant entry.
UN 3082 Environmentally Hazardous Substance Liquid NOS: Class 9 marine pollutant entry.
UN 3090 Lithium Metal Batteries: Class 9.
UN 3091 Lithium Metal Batteries Contained in Equipment or Packed with Equipment: Class 9.
UN 3148 Water-reactive Liquid NOS: Class 4.3.
UN 3164 Articles Pressurized Pneumatic or Hydraulic: Class 2.2.
UN 3166 Vehicle Flammable Liquid Powered or Flammable Gas Powered: Class 9 entry for motor vehicles.
UN 3171 Battery-powered Vehicle: Class 9 covering electric vehicles transported with installed batteries.
UN 3245 Genetically Modified Microorganisms or Organisms: Class 9.
UN 3257 Elevated Temperature Liquid NOS: Class 9, at or above 100 deg C and below its flashpoint.
UN 3258 Elevated Temperature Solid NOS: Class 9, at or above 240 deg C.
UN 3373 Biological Substance Category B: Class 6.2, packed under P650.
UN 3480 Lithium-ion Batteries: Class 9, including lithium-ion polymer.
UN 3481 Lithium-ion Batteries Contained in Equipment or Packed with Equipment: Class 9.
UN 3528 Engine, Internal Combustion, Flammable Liquid Powered: Class 3 entry for standalone engines and machinery.
UN 3529 Engine, Internal Combustion, Flammable Gas Powered: Class 2.1 entry for standalone engines.
UN 3530 Engine, Internal Combustion: Class 9 for engines not falling under 3528/3529.
UN 3531 Polymerizing Substance Solid Stabilized NOS: Class 4.1.
UN 3532 Polymerizing Substance Liquid Stabilized NOS: Class 4.1.
UN 3533 Polymerizing Substance Solid Temperature Controlled NOS: Class 4.1.
UN 3534 Polymerizing Substance Liquid Temperature Controlled NOS: Class 4.1.
UN Cylinder Mark: Permanent mark on Class 2 cylinders per 6.2.2 indicating standard, manufacturer, working pressure, and approval.
UN Manual of Tests and Criteria: UN publication providing classification test methods referenced by IMDG.
UN number: Number identifying dangerous goods under UN model regulations.
UN Recommendations on the Transport of Dangerous Goods (Model Regulations): The basis for IMDG, ADR, RID, ICAO TI, and IATA DGR, ensuring multimodal harmonisation.
UN Specification Packaging Mark: A mark such as "UN 4G/Y15/S/24/D/BAM 1234" denoting packaging type, performance level, gross mass, year, country, and approval reference.
Unpackaged Articles: Large robust articles transported without packaging under Chapter 4.1.3.8 for certain Class 1 articles or unpackaged solids.

V

Vapour Density: A property informing Class 2.3 toxic gas stowage and ventilation planning; gases denser than air collect in low spaces.
Vapour Pressure (Tank Design): The reference vapour pressure used in portable tank design per 6.7.2 and 6.7.3.
Vehicle Carrier Provisions: Provisions in 7.5 for ships specifically constructed and equipped for the carriage of motor vehicles, including UN 3166 and UN 3171 entries.
Vermiculite: Often used as absorbent cushioning material in combination packagings for liquid Class 3 or 6.1.
Viscous Substance Exemption: An exemption in 2.3.2.5 from Class 3 for certain viscous liquids meeting solvent separation and flashpoint criteria.
Volume 1 (IMDG): Contains Part 1 General, Part 2 Classification, Part 4 Packing and Tank Provisions, Part 5 Consignment Procedures, Part 6 Construction and Testing of Packagings, and Part 7 Operational Provisions.
Volume 2 (IMDG): Contains Part 3 Dangerous Goods List, Limited and Excepted Quantities exceptions, with the index and appendices.

W

Water Spray (Fire): Recommended extinguishing media in many EmS schedules; not permitted for Class 4.3 due to flammable gas evolution.
Water-reactive Liquid NOS UN 3148: A Class 4.3 not otherwise specified entry, packing group I, II, or III.
Water-reactive Solid NOS UN 2813: Class 4.3 generic entry for water-reactive solids that emit flammable gas.
Wave Height Allowance: Not formally defined in IMDG; stowage planning considers ship motions and bilge water access for damaged packages.
Wetted Explosives: Class 1 substances such as UN 0072 cyclonite wetted with not less than 15 per cent water by mass, reclassified to Class 4.1 only when properly wetted.

X

X Performance Level: UN packaging marking indicating suitability for Packing Groups I, II and III.
X-ray Inspection (CTU): A non-destructive screening method recommended in 7.8 for verifying segregation and load distribution in CTUs.

Y

Y Performance Level: UN packaging marking indicating suitability for Packing Groups II and III.
Yellow Label (Class 7): Yellow upper half on Categories II-YELLOW and III-YELLOW Class 7 labels indicating measurable surface radiation level.

Z

Z Performance Level: UN packaging marking indicating suitability for Packing Group III only.
Zero Radiation Reading: A condition for Class 7 Category I-WHITE labels indicating dose rate at surface not exceeding 0.005 mSv/h.