UN Hazard Class 1
Definition
The United Nations dangerous-goods classification for explosives. Divided into six divisions (1.1 through 1.6) based on mass explosion hazard, projection hazard, and fire hazard. Governs international transport and is referenced in all major national explosives regulatory frameworks.
- Divisions
- 1.1 to 1.6, by mass explosion, projection and fire hazard
- Scope
- International transport of explosives by road, rail, sea and air
- Basis
- UN Recommendations on the Transport of Dangerous Goods
- Use in casework
- Referenced when classifying seized or recovered explosive material
Common questions
Why does the division number matter for an investigator?+
The division sets handling, storage and transport rules, so it affects how safely a recovered device or bulk material can be moved and where it can be stored pending analysis, not just how it is labelled.
Is 1.1 always more dangerous than 1.4?+
Yes in terms of mass explosion risk. Division 1.1 material can detonate as a whole mass, while 1.4 covers items with only a minor blast hazard confined mostly to the package, such as some ammunition.
Related terms
- Brisance
- The shattering power of a detonating explosive, distinct from heave (bulk displacement). Measured by the Trauzl lead block test. High-brisance explosives (RDX,...
- Chapman-Jouguet Velocity
- The minimum stable detonation velocity for a given explosive at a specific density, a thermodynamic property of the explosive composition. Used to...
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Detonation
- A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100...
- Oxygen Balance
- A percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2...
- PESO (India)
- Petroleum and Explosives Safety Organisation, the Indian government body under the Ministry of Commerce and Industry that administers the Explosives Act 1884...
- Primary Explosive
- A high explosive sensitive enough to detonate from friction, spark, percussion, or flame without confinement or a separate booster. Examples: mercury fulminate,...
- Secondary Explosive
- A high explosive insensitive to normal friction, spark, and percussion; requires a primary explosive shock or blasting cap to initiate detonation. Examples:...
- Smokeless Propellant
- A low explosive based on nitrocellulose (single-base), nitrocellulose plus nitroglycerin (double-base), or nitrocellulose plus nitroglycerin plus nitroguanidine (triple-base). Used as firearm propellant...