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 8
IMO Class 8 - Corrosive substances
Class 8: Corrosive substances
Corrosives
1. For the purpose of this subchapter "corrosive materials" (Class 8) means a liquid or solid that causes full thickness destruction of human skin at the site of contact within a specified period of time. A liquid that has a severe corrosion rate on steel or aluminum is also a corrosive material.
2. If human experience or other data indicate that the hazard of a material is greater or less than indicated by the results of the tests specified in paragraph (a) of this section, RSPA may revise its classification or make the determination that the material is not subject to the requirements of this subchapter.
3. Skin corrosion test data produced no later than September 30, 1995, using the procedures of 49CFR 173, Appendix A, in effect on September 30, 1995 (see 49CFR Part 173, Appendix A, revised as of October 1, 1994) for appropriate exposure times may be used for classification and assignment of packing group for Class 8 materials corrosive to skin.
454 kg (1001 lbs) or more gross weight of a corrosive material. Although the corrosive class includes both acids and bases, the hazardous materials load and segregation chart does not make any reference to the separation of various incompatible corrosive materials from each other. In spite of this, however, when shipping corrosives care should be taken to ensure that incompatible corrosive materials can not become mixed as many corrosives react very violently if mixed. If responding to a transportation incident involving corrosive materials (especially a mixture of corrosives), caution should be exercised.
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?
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