The International Maritime Dangerous Goods (IMDG) Code is the IMO's mandatory standard for classifying, packing, marking, and stowing dangerous goods carried by sea. It assigns every hazardous substance a class, a UN number, and packing requirements that carriers and terminals must follow.
IMDG · Class 5
IMO Class 5 - Oxidizing Agents and Organic Peroxides
Class 5 Oxidizing Agents and Organic Peroxides
Subclass 5.1: Oxidizing Agent
Oxidizer (Division 5.1) means a material that may, generally by yielding oxygen, cause or enhance the combustion of other materials.
1. A solid material is classed as a Division 5.1 material if, when tested in accordance with the UN Manual of Tests and Criteria, its mean burning time is less than or equal to the burning time of a 3:7 potassium bromate/cellulose mixture.
2. A liquid material is classed as a Division 5.1 material if, when tested in accordance with the UN Manual of Tests and Criteria, it spontaneously ignites or its mean time for a pressure rise from 690 kPa to 2070 kPa gauge is less then the time of a 1:1 nitric acid (65 percent)/cellulose mixture.
Subclass 5.2: Organic peroxides - most will burn rapidly
and are sensitive to impact or friction
Organic peroxide (Division 5.2) means any organic compound containing oxygen (O) in the bivalent -O-O- structure and which may be considered a derivative of hydrogen peroxide, where one or more of the hydrogen atoms have been replaced by organic radicals, unless any of the following paragraphs applies:
1. The material meets the definition of an explosive as prescribed in subpart C of this part, in which case it must be classed as an explosive;
2. The material is forbidden from being offered for transportation according to 49CFR 172.101 of this subchapter or 49CFR 173.21;
3. The Associate Administrator for Hazardous Materials Safety has determined that the material does not present a hazard which is associated with a Division 5.2 material; or
4. The material meets one of the following conditions:
1. For materials containing no more than 1.0 percent hydrogen peroxide, the available oxygen, as calculated using the equation in paragraph (a)(4)(ii) of this section, is not more than 1.0 percent, or
2. For materials containing more than 1.0 percent but not more than 7.0 percent hydrogen peroxide
FAQ
Dangerous goods classification, explained
A substance is classed by its primary hazard, but many also carry a subsidiary risk — a toxic gas that's also flammable, for instance. The shipping documents and placarding reflect both, and segregation rules account for whichever hazard is more restrictive.
The UN number is assigned per substance (or group of similar substances) in the IMDG Code's Dangerous Goods List, not per class — two shipments in the same class can have different numbers, packing groups, and segregation requirements.
No — this is a plain-language reference for planning purposes only. Final classification, packing instructions, and stowage/segregation tables always come from the current edition of the IMDG Code and your carrier's dangerous goods desk.
Tracking a dangerous goods shipment?
Qubictron's tracking tools work the same way regardless of cargo class — see live status across ocean and air in one search.