☣️ UN 0305 • CLASS 1

UN 0305 — Flash powder

Placard: Explosive 1.3G. ERG Guide 112. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

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⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.

UN 0305 is Flash powder, a Class 1 explosive article assigned to ERG Guide 112. It is primarily a fire and deflagration hazard, with intense heat, smoke and possible fragment projection if ignited.

Hazard overview: UN 0305 is not normally treated as a mass explosion hazard when transported as classified, but it can burn intensely and may project fragments or ignite nearby explosive or pyrotechnic materials. Smoke can contain irritating or toxic combustion products, and damaged packages may increase the hazard.

Response guidance: For a UN 0305 incident, responders should confirm the article using shipping papers, markings and ERG Guide 112. Isolate the area, stay upwind, avoid smoke, control ignition sources when safe and determine whether higher-hazard explosives or larger quantities are also present before committing crews.

Firefighter training notes: Training should emphasize pyrotechnic and propellant fire behavior, fragment or thrust potential, smoke hazards and the risk of initiating nearby explosive articles. Common errors include approaching through smoke, standing in projection paths, underestimating packaged quantities and failing to expand isolation when fire spreads.

Regulatory context: Flash powder is regulated as a Class 1 explosive article. Transportation, storage, quantity and fire code requirements may apply depending on packaging and jurisdiction. Responders should verify current requirements through shipping papers, product documents and applicable DOT, ATF, OSHA, NFPA or local authority guidance.

Storage & handling: Flash powder should be stored in approved packaging or explosive storage areas away from heat, sparks, flame, friction, incompatible explosives and unauthorized access. Keep packages dry, protected from physical damage and segregated according to explosive compatibility requirements.

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UN 0305 Quick Details

UN 0305
Product name: Flash powder
DOT Class: 1
Placard type: Explosive 1.3G
ERG Guide: 112 (check current ERG)
Initial isolation: ERG 112: Initial isolation 500 meters (1600 feet) in all directions; if fire or large spill, evacuate 1600 meters (1 mile) downwind; treat as explosive hazard

Common Hazards of UN 0305

  • Fire and deflagration hazard; flash powder may ignite violently and produce intense heat and light.
  • May project burning particles or fragments and ignite nearby pyrotechnic or combustible materials.
  • Metal-fuel formulations may react poorly with unsuitable extinguishing agents.
  • Smoke may contain irritating or toxic combustion products.
  • Heat, friction, contamination or damaged packaging may increase ignition sensitivity.
  • Large quantities can create severe fire exposure and require expanded isolation.

Chemical Identity & Physical Properties

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.

Also known asPhotoflash compositionPyrotechnic flash compositionMagnesium-based flash powderPerchlorate flash powder
AppearanceFine 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 PointNot applicable (pyrotechnic solid - ignites upon suitable initiation)
Boiling PointNot applicable (decomposes/deflagrates upon heating)
Vapor DensityNot applicable (solid powder)
Water ReactivityAvoid water contact with magnesium-based compositions; may react slowly producing hydrogen gas and heat
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 0305

Extinguishing Media

Use only compatible dry agents from a safe distance when directed by incident command; avoid water, foam or CO2 if the specific flash powder formulation is unknown.

PPE Requirements

⚠️ Structural firefighting gear with SCBA for smoke or fire exposure; maintain standoff distance and expand evacuation if other explosives are nearby.

Responders should use structural firefighting gear with SCBA for smoke or fire exposure and maintain standoff distance from burning articles or packages. PPE does not replace evacuation if additional explosives or large quantities are involved.

Isolation & Evacuation

ERG 112: Initial isolation 500 meters (1600 feet) in all directions; if fire or large spill, evacuate 1600 meters (1 mile) downwind; treat as explosive hazard
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 112).

First Actions for a UN 0305 Incident

  • CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
  • Keep unauthorized personnel away and deny entry.
  • Stage upwind and avoid smoke from burning pyrotechnic, propellant or explosive material.
  • Eliminate ignition sources if it is safe to do so.
  • Isolate the area and check for nearby explosives, ammunition, rockets, propellants or pyrotechnic articles.
  • Protect exposures only from a safe distance if directed by incident command.
  • Use ERG Guide 112, shipping papers and incident command to set isolation and evacuation distances.
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📋 Copy & Share Field Card

UN 0305 — Flash powder
HAZMAT RADIO NOTE — UN 0305 Product: Flash powder Class 1 / Explosive 1.3G / ERG 112 PPE: Structural firefighting gear with SCBA for smoke or fire exposure; maintain standoff distance and expand evacuation if other explosives are nearby. ISOLATION: ERG 112: Initial isolation 500 meters (1600 feet) in all directions; if fire or large spill, evacuate 1600 meters (1 mile) downwind; treat as explosive hazard ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 0305 — Flash powder Class: 1 | Placard: Explosive 1.3G | ERG Guide: 112 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. Water Reactivity: Avoid water contact with magnesium-based compositions; may react slowly producing hydrogen gas and heat Extinguishing: Use only compatible dry agents from a safe distance when directed by incident command; avoid water, foam or CO2 if the specific flash powder formulation is unknown. PPE: Structural firefighting gear with SCBA for smoke or fire exposure; maintain standoff distance and expand evacuation if other explosives are nearby. Isolation: ERG 112: Initial isolation 500 meters (1600 feet) in all directions; if fire or large spill, evacuate 1600 meters (1 mile) downwind; treat as explosive hazard — Key Hazards — • Fire and deflagration hazard; flash powder may ignite violently and produce intense heat and light. • May project burning particles or fragments and ignite nearby pyrotechnic or combustible materials. • Metal-fuel formulations may react poorly with unsuitable extinguishing agents. — First Actions — • CALL 911. Then call the emergency response telephone number on the shipping paper, if available. • Keep unauthorized personnel away and deny entry. • Stage upwind and avoid smoke from burning pyrotechnic, propellant or explosive material. • Eliminate ignition sources if it is safe to do so. SOURCE: allfirefighter.com/hazmat/un/flash-powder-un-0305 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN0305 Flash powder Cls1 ERG112 | allfirefighter.com/hazmat/un/flash-powder-un-0305SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS.

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/flash-powder-un-0305

Related UN Numbers in Class 1

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 0305

UN 0305 is Flash powder, a Class 1 explosive or pyrotechnic article assigned to ERG Guide 112.

Not normally for this classification, but fire can cause intense burning, deflagration and fragment projection, especially if other explosives are nearby.

ERG Guide 112 applies to UN 0305.

The main hazards are intense fire, smoke, heat, localized fragments and ignition of nearby pyrotechnic, propellant or explosive materials.

Structural firefighting gear with SCBA is recommended for smoke and fire exposure, while maintaining distance and using incident command direction.

Keep people away, stage upwind, avoid smoke, control ignition sources, check for nearby explosives and follow ERG 112 and local SOP.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles. This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.