☣️ UN 0191 • CLASS 1

UN 0191 — Signal devices, hand

Placard: Explosive 1.4G. ERG Guide 114. 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 0191 covers small handheld pyrotechnic devices designed to produce smoke, light, or flame for signaling, and are classified as Division 1.4G explosives with a minor blast or fire hazard. These cylindrical devices contain combustible materials that can undergo localized burning or deflagration if improperly handled or exposed to heat.

Hazard overview: These devices present a localized fire and deflagration hazard, capable of producing smoke and heat if ignited, though their explosive effect is limited in scope. Some formulations may contain water-reactive pyrotechnic compounds, meaning exposure to moisture can trigger accidental ignition.

Response guidance: Establish an isolation perimeter of at least 25 meters in all directions from any UN 0191 incident, and expand evacuation to 800 meters if fire or explosion is involved. Apply water spray only from a safe distance and use dry chemical or sand as alternatives, avoiding direct water application on actively burning pyrotechnic devices.

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UN 0191 Quick Details

UN 0191
Product name: Signal devices, hand
DOT Class: 1
Placard type: Explosive 1.4G
ERG Guide: 114 (check current ERG)
Initial isolation: ERG 114: isolate 25m in all directions; if fire or explosion involved, evacuate 800m in all directions

Common Hazards of UN 0191

  • 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

UN 0191 signal devices are small, typically cylindrical handheld pyrotechnic units that vary in color depending on their signal type and contain combustible materials engineered to generate smoke, light, or flame.

Also known asHand-held signal devicesHand flaresMarine distress signalsPyrotechnic signal devicesHand-held smoke signals
AppearanceSmall handheld pyrotechnic devices, typically cylindrical, containing combustible materials designed to produce smoke, light, or flame for signaling purposes. Various colors depending on signal type.
Flash PointNot applicable (pyrotechnic device)
Boiling PointNot applicable (solid pyrotechnic composition)
Vapor DensityNot applicable (solid device)
Water ReactivityMay contain water-reactive pyrotechnic compounds; keep dry to prevent accidental ignition
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 0191

Extinguishing Media

Water spray from distance, dry chemical, sand; do not use water on burning pyrotechnics

PPE Requirements

⚠️ Structural firefighters' protective clothing with SCBA; eye and hand protection during handling

Responders handling UN 0191 devices must wear structural firefighters' protective clothing equipped with SCBA, along with appropriate eye and hand protection.

Isolation & Evacuation

ERG 114: isolate 25m in all directions; if fire or explosion involved, evacuate 800m in all directions
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 114).

First Actions for a UN 0191 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.
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📋 Copy & Share Field Card

UN 0191 — Signal devices, hand
HAZMAT RADIO NOTE — UN 0191 Product: Signal devices, hand Class 1 / Explosive 1.4G / ERG 114 PPE: Structural firefighters' protective clothing with SCBA; eye and hand protection during handling ISOLATION: ERG 114: isolate 25m in all directions; if fire or explosion involved, evacuate 800m in all directions 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 0191 — Signal devices, hand Class: 1 | Placard: Explosive 1.4G | ERG Guide: 114 Appearance: Small handheld pyrotechnic devices, typically cylindrical, containing combustible materials designed to produce smoke, light, or flame for signaling purposes. Various colors depending on signal type. Water Reactivity: May contain water-reactive pyrotechnic compounds; keep dry to prevent accidental ignition Extinguishing: Water spray from distance, dry chemical, sand; do not use water on burning pyrotechnics PPE: Structural firefighters' protective clothing with SCBA; eye and hand protection during handling Isolation: ERG 114: isolate 25m in all directions; if fire or explosion involved, evacuate 800m in all directions — Key Hazards — • Minor blast or fire hazard — limited effect. • Localized burning or deflagration possible. • Smoke and heat from burning. — First Actions — • CALL 911. Notify law enforcement. • Isolate area; keep unauthorized personnel away. • Stage upwind; eliminate ignition sources. • Request Hazmat + law enforcement. SOURCE: allfirefighter.com/hazmat/un/signal-devices-hand-un-0191 | Always use current ERG + SOP/SOGIC BRIEFING

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

SMS (short)
UN0191 Signal devices, hand Cls1 ERG114 | allfirefighter.com/hazmat/un/signal-devices-hand-un-0191SMS / 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/signal-devices-hand-un-0191

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 0191

UN 0191 is classified as a Division 1.4G explosive, meaning it presents a minor localized blast and fire hazard through deflagration rather than a mass explosion effect.

Responders must use structural firefighters' protective clothing with SCBA, plus eye and hand protection when handling UN 0191 signal devices.

ERG Guide 114 recommends isolating at least 25 meters in all directions and evacuating 800 meters if the devices are involved in fire or explosion.
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.