UN 0378 — Primers, cap type
Placard: Explosive 1.4B. ERG Guide 114. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0378 identifies cap-type primers, small impact-sensitive explosive devices housed in metallic cups or cylinders made of brass, copper, or aluminum. These Class 1.4B explosives present a limited, localized hazard but require careful handling due to their sensitivity to mechanical shock.
Hazard overview: UN 0378 poses a minor blast and fire hazard with effects confined to the immediate area, as deflagration rather than mass detonation is the expected failure mode. Localized burning may occur if primers are exposed to heat or direct flame, but the risk of sympathetic detonation of the entire load is low.
Response guidance: Establish an initial isolation zone of 100 meters in all directions; if fire is involved, expand the perimeter to 800 meters and consider evacuation within that radius. Apply water spray or fog to control fires and cool surrounding materials, and use dry chemical extinguishers for small, contained fires.
UN 0378 Quick Details
Common Hazards of UN 0378
- 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 0378 primers are small metallic cups or cylinders, typically brass, copper, or aluminum, containing a pressed impact-sensitive explosive compound in the base.
| Also known as | percussion capsprimer capsblasting capsignition primersdetonator caps |
| Appearance | Small metallic cups or cylinders containing a small amount of impact-sensitive explosive mixture. Typically brass, copper, or aluminum construction with pressed explosive compound inside. |
| Flash Point | Not applicable (explosive device) |
| Boiling Point | Not applicable (explosive device) |
| Vapor Density | Not applicable (solid device) |
| Water Reactivity | No significant reaction with water, though water may be used for cooling or containment |
Fireground Response Guidance — UN 0378
Extinguishing Media
PPE Requirements
Wear Level C protection minimum for intact primer handling; upgrade to Level B with SCBA and add fragment-resistant gear if deflagration or fire has occurred.
Isolation & Evacuation
First Actions for a UN 0378 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 0378 — Primers, cap typeUse 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.