UN 0173 — Release devices, explosive
Placard: Explosive 1.4S. ERG Guide 114. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0173 covers release devices, explosive — small explosive assemblies engineered to mechanically separate or deploy components upon activation. These devices present a localized blast and fire hazard, particularly if subjected to heat, impact, or damage during a transportation incident.
Hazard overview: UN 0173 devices pose a minor blast and deflagration hazard, with any explosive effect typically limited to the immediate vicinity of the device. Burning devices may produce smoke, heat, and localized fire, but mass detonation propagation is not expected for Division 1.4S materials.
Response guidance: Responders should isolate a minimum of 200 meters in all directions from an incident involving UN 0173 and increase the isolation zone to 500 meters if devices are damaged, burning, or involved in fire. Small fires may be suppressed with water spray, foam, dry chemical, or CO2, but devices should never be moved or handled without confirmed stability.
UN 0173 Quick Details
Common Hazards of UN 0173
- 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 0173 release devices are solid metal or composite assemblies housing small explosive charges and are found in a variety of mechanical configurations depending on their intended separation or release function.
| Also known as | Explosive release devicesPyrotechnic release mechanismsExplosive actuatorsOrdnance release systems |
| Appearance | Metal or composite assemblies containing small explosive charges designed to mechanically release or separate components. Typically solid devices in various configurations. |
| Flash Point | Not applicable (explosive device) |
| Boiling Point | Not applicable (explosive device) |
| Vapor Density | Not applicable (solid device) |
| Water Reactivity | No significant reaction under normal conditions |
Fireground Response Guidance — UN 0173
Extinguishing Media
PPE Requirements
Level C protection is the minimum for handling intact UN 0173 devices, but Level B with SCBA is required if devices are damaged, burning, or releasing combustion products.
Isolation & Evacuation
First Actions for a UN 0173 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 0173 — Release devices, explosiveUse 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.