IMDG dangerous-goods classification for explosive substances and articles.
In practice
Class 1 explosives are heavily regulated; segregation tables in the IMDG Code dictate stowage. The cargo officer signs the dangerous-goods declaration; the IMDG Code specifies CTU packing.
Regulatory detail & full definition
IMDG Class 1 is the dangerous-goods classification for explosive substances and articles under the International Maritime Dangerous Goods Code. It is split into six divisions, from 1.1 (mass-explosion hazard) down to 1.6 (extremely insensitive articles), and further into compatibility groups; examples include small-arms ammunition (1.4S), fireworks (1.4G) and industrial blasting explosives (1.1D). Stowage and segregation are tightly governed by the segregation table in IMDG Code Part 7, and because many ports refuse the higher divisions such as 1.1, specialised carriers are usually required.