☣️ UN 3224 • CLASS 4
Self-reactive solid type C
Placard: Flammable Solid. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ 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.
Advertisement
Quick details
UN 3224
Class: 4
Placard type: Flammable Solid
ERG: Guide 149 (check current ERG)
Isolation: ERG 149: isolate 50m in all directions; for fire, isolate 800m and consider evacuation in downwind direction; protect from heat, friction, and contamination
Chemical & Response Details
| Also known as | Self-reactive solid type COrganic peroxide type C solidSelf-accelerating decomposition materialSADM solid type C |
| Appearance | Solid material at room temperature, variable color depending on specific formulation. May be crystalline, granular, or powder form. Generally organic compounds with reactive functional groups. |
| Flash Point | Not applicable (self-reactive solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Generally no significant reaction with water, but may release heat; avoid large quantities of water which may spread decomposition |
| Extinguishing | Dry chemical, sand, or inert material preferred; avoid water streams; CO2 may be used for small fires |
| PPE | ⚠️ Level B minimum recommended; SCBA required in all fire or decomposition scenarios; heat-resistant protective clothing if exposed to fire |
| Isolation | ERG 149: isolate 50m in all directions; for fire, isolate 800m and consider evacuation in downwind direction; protect from heat, friction, and contamination |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Self-decomposition, self-polymerization, or self-ignition may be triggered by heat, chemical
- May be ignited by heat, sparks or flames.
- Some may decompose explosively when heated or involved in a fire.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
- May burn violently. Decomposition or polymerization may be self-accelerating and produce large
- Vapors or dust may form explosive mixtures with air.
- Inhalation or contact with vapors, substance or decomposition products may cause severe injury or
- May produce irritating, toxic and/or corrosive gases.
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.
Advertisement
📋 Copy & Share
UN 3224 — Self-reactive solid type C HAZMAT RADIO NOTE — UN 3224
Product: Self-reactive solid type C
Class 4 / Flammable Solid / ERG 149
PPE: Level B minimum recommended; SCBA required in all fire or decomposition scenarios; heat-resistant protective clothing if exposed to fire
ISOLATION: ERG 149: isolate 50m in all directions; for fire, isolate 800m and consider evacuation in downwind direction; protect from heat, friction, and contamination
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 3224 — Self-reactive solid type C
Class: 4 | Placard: Flammable Solid | ERG Guide: 149
Appearance: Solid material at room temperature, variable color depending on specific formulation. May be crystalline, granular, or powder form. Generally organic compounds with reactive functional groups.
Water Reactivity: Generally no significant reaction with water, but may release heat; avoid large quantities of water which may spread decomposition
Extinguishing: Dry chemical, sand, or inert material preferred; avoid water streams; CO2 may be used for small fires
PPE: Level B minimum recommended; SCBA required in all fire or decomposition scenarios; heat-resistant protective clothing if exposed to fire
Isolation: ERG 149: isolate 50m in all directions; for fire, isolate 800m and consider evacuation in downwind direction; protect from heat, friction, and contamination
— Key Hazards —
• Self-decomposition, self-polymerization, or self-ignition may be triggered by heat, chemical
• May be ignited by heat, sparks or flames.
• Some may decompose explosively when heated or involved in a fire.
— 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/3224 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3224 Self-reactive solid type C Cls4 ERG149 | allfirefighter.com/hazmat/un/3224SMS / 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/3224
Advertisement
FAQ
Self-decomposition, self-polymerization, or self-ignition may be triggered by heat, chemical May be ignited by heat, sparks or flames. Some may decompose explosively when heated or involved in a fire. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. May burn violently. Decomposition or polymerization may be self-accelerating and produce large Vapors or dust may form explosive mixtures with air. Inhalation or contact with vapors, substance or decomposition products may cause severe injury or May produce irritating, toxic and/or corrosive gases.
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 recommended; SCBA required in all fire or decomposition scenarios; heat-resistant protective clothing if exposed to fire
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 149 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.