☣️ UN 0403 • CLASS 1

UN 0403 — Flares, aerial

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.
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UN 0403 Quick Details

UN 0403
Product name: Flares, aerial
DOT Class: 1
Placard type: Explosive 1.3G
ERG Guide: 112 (check current ERG)
Initial isolation: ERG 112: Initial isolation 500 meters in all directions; if fire or cargo involved in fire, consider evacuation for 1600 meters in all directions; protect from heat and ignition sources

Common Hazards of UN 0403

  • 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

Also known asAerial flaresSignal flaresPyrotechnic flaresIlluminating flaresDistress flares
AppearanceCylindrical pyrotechnic devices containing combustible materials and oxidizers, typically in metal or plastic housings. Designed to produce intense light and heat when ignited.
Flash PointNot applicable (pyrotechnic composition)
Boiling PointNot applicable (pyrotechnic composition)
Vapor DensityNot applicable (solid pyrotechnic device)
Water ReactivityMay contain water-reactive metals such as magnesium or aluminum; avoid water application on burning flares
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 0403

Extinguishing Media

Do not use water or foam; use dry sand, dry chemical, or soda ash to cover and smother; allow to burn out in controlled area if safe

PPE Requirements

⚠️ Full protective clothing and positive-pressure SCBA required; face shield and heat-resistant gloves; maintain safe distance due to intense heat and potential fragment projection

Isolation & Evacuation

ERG 112: Initial isolation 500 meters in all directions; if fire or cargo involved in fire, consider evacuation for 1600 meters in all directions; protect from heat and ignition sources
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 112).

First Actions for a UN 0403 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.
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📋 Copy & Share Field Card

UN 0403 — Flares, aerial
HAZMAT RADIO NOTE — UN 0403 Product: Flares, aerial Class 1 / Explosive 1.3G / ERG 112 PPE: Full protective clothing and positive-pressure SCBA required; face shield and heat-resistant gloves; maintain safe distance due to intense heat and potential fragment projection ISOLATION: ERG 112: Initial isolation 500 meters in all directions; if fire or cargo involved in fire, consider evacuation for 1600 meters in all directions; protect from heat and ignition sources 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 0403 — Flares, aerial Class: 1 | Placard: Explosive 1.3G | ERG Guide: 112 Appearance: Cylindrical pyrotechnic devices containing combustible materials and oxidizers, typically in metal or plastic housings. Designed to produce intense light and heat when ignited. Water Reactivity: May contain water-reactive metals such as magnesium or aluminum; avoid water application on burning flares Extinguishing: Do not use water or foam; use dry sand, dry chemical, or soda ash to cover and smother; allow to burn out in controlled area if safe PPE: Full protective clothing and positive-pressure SCBA required; face shield and heat-resistant gloves; maintain safe distance due to intense heat and potential fragment projection Isolation: ERG 112: Initial isolation 500 meters in all directions; if fire or cargo involved in fire, consider evacuation for 1600 meters in all directions; protect from heat and ignition sources — Key Hazards — • Fire and burning hazard — not mass explosion. • Intense heat and possible fragment projection. • May deflagrate and initiate other materials. — First Actions — • 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. SOURCE: allfirefighter.com/hazmat/un/0403 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN0403 Flares, aerial Cls1 ERG112 | ERG 112: Initial isolation 500 meters in all directions; if fire or cargo involv | allfirefighter.com/hazmat/un/0403SMS / 160 CHAR

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

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/0403

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 0403

Fire and burning hazard — not mass explosion. Intense heat and possible fragment projection. May deflagrate and initiate other materials. Smoke and toxic combustion products.

CALL 911. Then call emergency response telephone number on shipping paper. Isolate area; stage upwind — fire and fragment hazard. Request Hazmat + law enforcement.

Full protective clothing and positive-pressure SCBA required; face shield and heat-resistant gloves; maintain safe distance due to intense heat and potential fragment projection

Water reactivity: May contain water-reactive metals such as magnesium or aluminum; avoid water application on burning flares. Recommended extinguishing: Do not use water or foam; use dry sand, dry chemical, or soda ash to cover and smother; allow to burn out in controlled area if safe.

ERG Guide 112 recommendation: ERG 112: Initial isolation 500 meters in all directions; if fire or cargo involved in fire, consider evacuation for 1600 meters in all directions; protect from heat and ignition sources

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 112 and your department SOP/SOG for incident-specific protective actions.
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.