☣️ UN 3104 • CLASS 5

Organic peroxide type C, solid

Placard: Organic Peroxide. 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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Quick details
UN 3104
Class: 5
Placard type: Organic Peroxide
ERG: Guide 146 (check current ERG)
Isolation: ERG 146: Initially isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation for that distance
Chemical & Response Details
Also known asOrganic peroxide type C solidClass 5.2 organic peroxideSelf-reactive solid type CPeroxide compound solid
AppearanceTypically a white to off-white crystalline or granular solid. May be odorless or have a slight chemical odor. Physical appearance varies depending on specific compound, as this is a classification covering multiple organic peroxides.
Flash PointNot applicable (self-reactive solid that can decompose explosively)
Boiling PointNot applicable (decomposes before boiling)
Vapor DensityNot applicable (solid material)
Water ReactivityGenerally no significant reaction with water, but water may not effectively control decomposition or fires
ExtinguishingDry chemical, CO2, or water spray from distance; foam may be ineffective; avoid directing water stream directly onto material
PPE⚠️ Level B minimum required; SCBA and full protective clothing mandatory; face shield and thermal protection for fire fighting; evacuation of non-essential personnel
IsolationERG 146: Initially isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation for that distance
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • May explode from heat, shock, friction or contamination.
  • May ignite combustibles (wood, paper, oil, clothing, etc.).
  • May be ignited by heat, sparks or flames.
  • May burn rapidly with flare-burning effect.
  • Containers may explode when heated.
  • Runoff may create fire or explosion hazard.
  • Fire may produce irritating, corrosive and/or toxic gases.
  • Ingestion or contact (skin, eyes) with substance may cause severe injury or burns.
First actions (field-minded)
  • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
  • Keep unauthorized personnel away.
  • Stay upwind, uphill and/or upstream.
  • Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
  • Consider initial evacuation for at least 250 meters (800 feet) in all directions.
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UN 3104 — Organic peroxide type C, solid
HAZMAT RADIO NOTE — UN 3104 Product: Organic peroxide type C, solid Class 5 / Organic Peroxide / ERG 146 PPE: Level B minimum required; SCBA and full protective clothing mandatory; face shield and thermal protection for fire fighting; evacuation of non-essential personnel ISOLATION: ERG 146: Initially isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation for that distance 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 3104 — Organic peroxide type C, solid Class: 5 | Placard: Organic Peroxide | ERG Guide: 146 Appearance: Typically a white to off-white crystalline or granular solid. May be odorless or have a slight chemical odor. Physical appearance varies depending on specific compound, as this is a classification covering multiple organic peroxides. Water Reactivity: Generally no significant reaction with water, but water may not effectively control decomposition or fires Extinguishing: Dry chemical, CO2, or water spray from distance; foam may be ineffective; avoid directing water stream directly onto material PPE: Level B minimum required; SCBA and full protective clothing mandatory; face shield and thermal protection for fire fighting; evacuation of non-essential personnel Isolation: ERG 146: Initially isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation for that distance — Key Hazards — • May explode from heat, shock, friction or contamination. • May ignite combustibles (wood, paper, oil, clothing, etc.). • May be ignited by heat, sparks or flames. — First Actions — • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper • Keep unauthorized personnel away. • Stay upwind, uphill and/or upstream. • Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters SOURCE: allfirefighter.com/hazmat/un/3104 | 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)
UN3104 Organic peroxide type C, solid Cls5 ERG146 | allfirefighter.com/hazmat/un/3104SMS / 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/3104
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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FAQ

May explode from heat, shock, friction or contamination. May ignite combustibles (wood, paper, oil, clothing, etc.). May be ignited by heat, sparks or flames. May burn rapidly with flare-burning effect. Containers may explode when heated. Runoff may create fire or explosion hazard. Fire may produce irritating, corrosive and/or toxic gases. Ingestion or contact (skin, eyes) with substance may cause severe injury or burns.

CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.

Level B minimum required; SCBA and full protective clothing mandatory; face shield and thermal protection for fire fighting; evacuation of non-essential personnel

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 146 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.