UN 0377 — Primers, cap type
Placard: Explosive 1.1B. ERG Guide 112. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0377 is Primers, cap type, a Class 1 explosive assigned to ERG Guide 112. This entry should be treated as a high-consequence explosive hazard where isolation, evacuation and qualified explosive ordnance support are the primary responder priorities.
Hazard overview: UN 0377 presents a mass explosion hazard when exposed to fire, impact, shock, friction or other initiating conditions. A detonation may involve the entire load and produce severe blast pressure, fragmentation and secondary debris. Responders should not rely on normal firefighting PPE as protection from blast effects.
Response guidance: For a UN 0377 incident, responders should confirm the material using shipping papers, placards, package markings and ERG Guide 112. Establish incident command, isolate the area, deny entry, request law enforcement and EOD support, and withdraw personnel if fire involves the explosive material or containers.
Firefighter training notes: Training should emphasize recognizing Class 1 explosive placards, establishing command early, using standoff distance, denying entry and requesting bomb squad or EOD support. Common tactical errors include approaching packages for identification, moving damaged items, fighting fire too close and underestimating fragmentation distance. Use ERG 112, shipping papers and local explosive incident SOP.
Regulatory context: Primers, cap type is regulated as a Class 1 explosive hazardous material. Transport, storage, reporting and scene-control requirements may involve DOT, ATF, OSHA, military, state or local authorities depending on ownership and quantity. Responders should verify requirements through shipping papers, facility documents, law enforcement and current regulations.
Storage & handling: Primers, cap type should be stored only in approved explosive magazines or authorized storage areas, separated from ignition sources, incompatible materials and unauthorized access. Packages should be protected from heat, impact, friction, moisture where relevant and physical damage according to product documentation and applicable explosive storage regulations.
UN 0377 Quick Details
Common Hazards of UN 0377
- Mass explosion hazard; the entire load may detonate simultaneously if initiated.
- Severe blast overpressure, fragmentation and debris may extend far beyond the immediate container or vehicle.
- Explosive articles or substances may be sensitive to heat, shock, friction, impact or fire exposure.
- Fire involving the material can transition rapidly to detonation without reliable warning.
- Secondary fires, projectiles and container fragments may create hazards after an initial event.
- Smoke from fire may contain irritating or toxic combustion products.
Chemical Identity & Physical Properties
Small metallic cylindrical devices containing primary explosives, typically brass or aluminum construction with sensitive explosive composition inside.
| Also known as | Percussion capsBlasting capsInitiator capsDetonator primersCap-type primers |
| Appearance | Small metallic cylindrical devices containing primary explosives, typically brass or aluminum construction with sensitive explosive composition inside. |
| Flash Point | Not applicable (explosive article) |
| Boiling Point | Not applicable (explosive article) |
| Vapor Density | Not applicable (solid explosive device) |
| Water Reactivity | No significant reaction with water, but moisture may degrade explosive sensitivity over time |
Fireground Response Guidance — UN 0377
Extinguishing Media
PPE Requirements
For UN 0377, distance, cover and evacuation are more important than close-range PPE. Structural firefighting gear and SCBA may be used only for remote exposure protection or support roles; direct approach or handling should be limited to qualified EOD or explosive specialists under incident command.
Isolation & Evacuation
First Actions for a UN 0377 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away and deny entry to the hazard area.
- Stage responders upwind, uphill and outside the recommended isolation distance.
- Request law enforcement, bomb squad or EOD, hazmat and additional command resources immediately.
- Do not handle, move or disturb explosive articles unless directed by qualified explosive ordnance personnel.
- Do not fight fire involving explosives at close range; withdraw and protect life safety first.
- Protect exposures only from a safe, remote position if directed by incident command and local SOP.
- Use ERG Guide 112, shipping papers and incident command to set isolation and evacuation distances.
📋 Copy & Share Field Card
UN 0377 — 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.