☣️ UN 3234 • CLASS 4
UN 3234 — Self-reactive solid type C, temperature controlled
Placard: Flammable Solid. ERG Guide 150. 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 3234 Quick Details
UN 3234
Product name: Self-reactive solid type C, temperature controlled
DOT Class: 4
Placard type: Flammable Solid
ERG Guide: 150 (check current ERG)
Initial isolation: ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins
Common Hazards of UN 3234
- Self-decomposition, self-polymerization, or self-ignition may be triggered by heat, chemical
- Self-accelerating decomposition may occur if the specific "control temperature" is not maintained.
- These materials are particularly sensitive to temperature rises. Above a given "Control Temperature"
- May be ignited by heat, sparks or flames.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
- Some may decompose 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.
Chemical Identity & Physical Properties
| Also known as | Self-reactive solid type CTemperature controlled organic peroxideSelf-accelerating decomposition materialSADT organic solid |
| Appearance | Solid material of varying color depending on specific compound; may be crystalline, powder, or granular form at room temperature; requires temperature control during transport and storage. |
| Flash Point | Not applicable (self-reactive solid - decomposition rather than ignition) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Varies by specific compound; generally no violent reaction with water but may contaminate runoff |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3234
Extinguishing Media
Dry chemical, CO2, water spray for cooling only; avoid materials that may accelerate decomposition
PPE Requirements
⚠️ Level B minimum with SCBA; full structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously
Isolation & Evacuation
ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 150).
First Actions for a UN 3234 Incident
- 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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📋 Copy & Share Field Card
UN 3234 — Self-reactive solid type C, temperatureHAZMAT RADIO NOTE — UN 3234
Product: Self-reactive solid type C, temperature controlled
Class 4 / Flammable Solid / ERG 150
PPE: Level B minimum with SCBA; full structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously
ISOLATION: ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins
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 3234 — Self-reactive solid type C, temperature controlled
Class: 4 | Placard: Flammable Solid | ERG Guide: 150
Appearance: Solid material of varying color depending on specific compound; may be crystalline, powder, or granular form at room temperature; requires temperature control during transport and storage.
Water Reactivity: Varies by specific compound; generally no violent reaction with water but may contaminate runoff
Extinguishing: Dry chemical, CO2, water spray for cooling only; avoid materials that may accelerate decomposition
PPE: Level B minimum with SCBA; full structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously
Isolation: ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins
— Key Hazards —
• Self-decomposition, self-polymerization, or self-ignition may be triggered by heat, chemical
• Self-accelerating decomposition may occur if the specific "control temperature" is not maintained.
• These materials are particularly sensitive to temperature rises. Above a given "Control Temperature"
— 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/3234 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3234 Self-reactive solid type C, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/3234SMS / 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/3234
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Frequently Asked Questions about UN 3234
Self-decomposition, self-polymerization, or self-ignition may be triggered by heat, chemical Self-accelerating decomposition may occur if the specific "control temperature" is not maintained. These materials are particularly sensitive to temperature rises. Above a given "Control Temperature" May be ignited by heat, sparks or flames. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Some may decompose 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.
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 with SCBA; full structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously
Water reactivity: Varies by specific compound; generally no violent reaction with water but may contaminate runoff. Recommended extinguishing: Dry chemical, CO2, water spray for cooling only; avoid materials that may accelerate decomposition.
ERG Guide 150 recommendation: ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 150 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.