UN 0373 — Signal devices, hand
Placard: Explosive 1.4S. ERG Guide 114. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0373 is Signal devices, hand, a Class 1.4 explosive article assigned to ERG Guide 114. It is a limited-effect pyrotechnic or signal device with localized fire, smoke and projection hazards.
Hazard overview: UN 0373 primarily presents a smoke, heat and localized deflagration hazard. Dense smoke can reduce visibility and irritate the respiratory tract, while fire or damaged packaging may cause popping, small fragments or ignition of nearby pyrotechnic articles.
Response guidance: For a UN 0373 incident, responders should confirm the device using shipping papers, markings and ERG Guide 114. Isolate the area, keep unprotected people out of the smoke path, stay upwind, avoid handling damaged devices and expand the perimeter if fire involves multiple units.
Firefighter training notes: Training should emphasize the difference between 1.4 limited-effect explosives and higher-hazard Class 1 materials. Common errors include standing too close to heated packages, dismissing smoke hazards, disturbing damaged articles and failing to check for adjacent explosives or ammunition.
Regulatory context: Signal devices, hand is regulated as a Class 1 explosive article for transportation. Storage, quantity limits, fire code controls and reporting requirements may vary by jurisdiction. Responders should verify current requirements through shipping papers, product documents and applicable DOT, ATF, OSHA, NFPA or local authority guidance.
Storage & handling: Signal devices, hand should be stored in compatible packaging away from heat, sparks, open flame, impact and unauthorized access. Keep separated from incompatible explosives, propellants and combustible clutter according to product instructions and local fire code.
UN 0373 Quick Details
Common Hazards of UN 0373
- Minor explosive and fire hazard with effects usually limited to the device or package.
- Dense smoke may reduce visibility and irritate the eyes or respiratory tract.
- Localized burning, deflagration, popping or small fragments may occur if heated.
- Low mass explosion risk under normal transport conditions.
- Heated packages may fail and scatter small articles or fragments.
- Nearby explosives, ammunition or pyrotechnics may increase the overall incident hazard.
Chemical Identity & Physical Properties
Small cylindrical or tube-shaped devices, typically red or orange colored, containing pyrotechnic compositions that produce colored flames or smoke when ignited.
| Also known as | Hand-held signal devicesHandheld flaresMarine distress signalsHand signal flaresPyrotechnic signal devices |
| Appearance | Small cylindrical or tube-shaped devices, typically red or orange colored, containing pyrotechnic compositions that produce colored flames or smoke when ignited. |
| Flash Point | Not applicable (pyrotechnic device) |
| Boiling Point | Not applicable (pyrotechnic device) |
| Vapor Density | Not applicable (solid pyrotechnic) |
| Water Reactivity | May react with water depending on composition; keep dry during storage |
Fireground Response Guidance — UN 0373
Extinguishing Media
PPE Requirements
Structural firefighting protective clothing with SCBA is appropriate for fire or smoke exposure, with distance maintained from heated packages. Approach and handling should follow incident command and local SOP.
Isolation & Evacuation
First Actions for a UN 0373 Incident
- CALL 911. Notify law enforcement if ammunition components, explosive articles or ordnance are involved.
- Keep unauthorized personnel away.
- Stage upwind and avoid smoke from burning articles.
- Move unprotected people out of the smoke path when safe and practical.
- Eliminate ignition sources if it is safe to do so.
- Isolate the area and expand the perimeter if fire grows or additional explosives are present.
- Use ERG Guide 114, shipping papers and incident command for isolation and fire response decisions.
📋 Copy & Share Field Card
UN 0373 — Signal devices, handUse 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.