UN 0305 — Flash powder
Placard: Explosive 1.3G. ERG Guide 112. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0305, Flash Powder, is a pyrotechnic explosive composition typically consisting of finely milled aluminum or magnesium metal combined with an oxidizer such as potassium perchlorate. Classified as Division 1.3G, it presents serious fire, deflagration, and fragment projection hazards requiring immediate and specialized emergency response.
Hazard overview: Flash Powder can deflagrate with extreme intensity, producing blinding light output and dangerous heat projection capable of initiating adjacent explosive or flammable materials. Although not expected to mass detonate, burning material may project burning fragments and initiate secondary fires or sympathetic reactions in nearby pyrotechnic stocks.
Response guidance: Establish an initial isolation zone of 500 meters in all directions and evacuate at least 1600 meters downwind if fire or large-scale involvement is confirmed per ERG Guide 112. Suppress burning Flash Powder only with dry sand, dry chemical powder, or dry earth — never apply water, foam, CO2, or halogenated agents, as these can intensify the reaction or release hydrogen gas from magnesium-based compositions.
UN 0305 Quick Details
Common Hazards of UN 0305
- Fire and burning hazard — not mass explosion.
- Intense heat and possible fragment projection.
- May deflagrate and initiate other materials.
- Smoke and toxic combustion products.
Chemical Identity & Physical Properties
Flash Powder appears as a fine gray to silver metallic powder or granular solid, odorless under normal conditions, composed of metallic fuel particles uniformly blended with a solid oxidizer.
| Also known as | Photoflash compositionPyrotechnic flash compositionMagnesium-based flash powderPerchlorate flash powder |
| Appearance | Fine gray to silver metallic powder mixture, typically consisting of aluminum or magnesium metal with an oxidizer (usually potassium perchlorate). Odorless in pure form. Appears as loose granular or powdered solid at room temperature. |
| Flash Point | Not applicable (pyrotechnic solid - ignites upon suitable initiation) |
| Boiling Point | Not applicable (decomposes/deflagrates upon heating) |
| Vapor Density | Not applicable (solid powder) |
| Water Reactivity | Avoid water contact with magnesium-based compositions; may react slowly producing hydrogen gas and heat |
Fireground Response Guidance — UN 0305
Extinguishing Media
PPE Requirements
Responders require a minimum Level B ensemble with full-face SCBA, fire-resistant structural firefighting gear, and ballistic or blast-rated shielding due to intense flash output and potential fragment projection from deflagrating material.
Isolation & Evacuation
First Actions for a UN 0305 Incident
- CALL 911. Then call emergency response telephone number on shipping paper.
- Isolate area; stage upwind — fire and fragment hazard.
- Request Hazmat + law enforcement.
- Control ignition sources; deny entry.
- Consult current ERG Guide 112 and follow SOP/SOG.
📋 Copy & Share Field Card
UN 0305 — Flash powderUse 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.