UN 0405 — Cartridges, signal
Placard: Explosive 1.4S. ERG Guide 114. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0405 signal cartridges are small cylindrical pyrotechnic devices in metal or plastic casings designed to produce colored smoke, flame, or light signals, classified as Division 1.4S—the least hazardous explosive classification, indicating that any hazardous effects are largely confined to the package itself. Despite their low classification, these cartridges contain pyrotechnic compositions that can include water-reactive compounds and should be handled with appropriate precaution.
Hazard overview: UN 0405 cartridges present a localized deflagration and fire hazard; while mass detonation is not expected, burning cartridges can project burning stars or hot debris and may produce toxic combustion products from pyrotechnic compositions. Water-reactive components within the pyrotechnic fill can react violently if water is applied to actively burning cartridges.
Response guidance: ERG Guide 114 calls for an initial isolation of 25 meters in all directions; if cargo is involved in fire, increase isolation to 800 meters and evaluate the need for broader evacuation. Extinguish with dry chemical, sand, or smothering agents and strictly avoid water application on burning cartridges containing water-reactive pyrotechnic compounds.
UN 0405 Quick Details
Common Hazards of UN 0405
- 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
Signal cartridges are small solid-state devices at ambient temperature, constructed of metal or plastic casings enclosing pyrotechnic compositions formulated to emit colored smoke, flame, or light on activation.
| Also known as | Signal cartridgesPyrotechnic signal devicesFlare cartridgesDistress signal cartridges |
| Appearance | Small cylindrical devices containing pyrotechnic compositions, typically metal or plastic cased. Designed to produce colored smoke, flame, or light signals. Solid at room temperature. |
| Flash Point | Not applicable (pyrotechnic device) |
| Boiling Point | Not applicable (pyrotechnic solid) |
| Vapor Density | Not applicable (solid device) |
| Water Reactivity | May contain water-reactive pyrotechnic compounds; avoid water contact during fire |
Fireground Response Guidance — UN 0405
Extinguishing Media
PPE Requirements
Structural firefighters' protective clothing with SCBA is required under fire conditions; eye protection and chemical-resistant gloves are the minimum for routine handling operations.
Isolation & Evacuation
First Actions for a UN 0405 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 0405 — Cartridges, signalUse 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.