UN 0255 — Detonators, electric, for blasting
Placard: Explosive 1.4B. ERG Guide 114. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0255 covers electric detonators for blasting, also known as electric blasting caps or electrical initiators, which are small cylindrical devices containing primary and secondary explosive charges activated by an electrical current. These devices are classified as Division 1.4B explosives, indicating a minor blast or fire hazard with effects generally confined to the immediate vicinity of the device.
Hazard overview: UN 0255 electric detonators present a localized blast and deflagration risk, with the primary danger being mass detonation if multiple units are involved in a fire or shock event. Burning detonators can produce smoke and heat, and while water reactivity is not a concern, moisture may compromise the electrical firing circuit and affect device behavior unpredictably.
Response guidance: Responders to a UN 0255 incident should isolate the area to a minimum of 200 meters in all directions and expand evacuation to an 800-meter radius if fire is directly involving the detonators. Water spray may be used cautiously for cooling surrounding materials, but direct water streams onto the detonators themselves should be avoided to prevent unpredictable initiation or degradation.
UN 0255 Quick Details
Common Hazards of UN 0255
- Minor blast or fire hazard — limited effect.
- Localized burning or deflagration possible.
- Smoke and heat from burning.
- Low mass explosion risk under normal conditions.
Chemical Identity & Physical Properties
UN 0255 electric detonators are small cylindrical devices housed in aluminum, copper, or plastic shell casings with attached electrical lead wires used to initiate the explosive charge remotely.
| Also known as | Electric blasting capsElectric detonatorsElectrical initiatorsElectric explodersBlasting machine detonators |
| Appearance | Small cylindrical metal or plastic devices containing primary and secondary explosive charges with attached electrical wires. Typically aluminum, copper, or plastic shell casings. |
| Flash Point | Not applicable (explosive device) |
| Boiling Point | Not applicable (explosive device) |
| Vapor Density | Not applicable (solid explosive device) |
| Water Reactivity | No significant reaction with water, but moisture may degrade electrical function |
Fireground Response Guidance — UN 0255
Extinguishing Media
PPE Requirements
Responders must wear full structural firefighting gear with SCBA at a minimum, with Level C chemical protection considered for transport incidents involving UN 0255 electric detonators, while maintaining a safe standoff distance from any suspected explosive hazard.
Isolation & Evacuation
First Actions for a UN 0255 Incident
- CALL 911. Notify law enforcement.
- Isolate area; keep unauthorized personnel away.
- Stage upwind; eliminate ignition sources.
- Request Hazmat + law enforcement.
- Consult current ERG Guide 114 and follow SOP/SOG.
📋 Copy & Share Field Card
UN 0255 — Detonators, electric, for blastingUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.