☣️ UN 3232 • CLASS 4
Self-reactive solid type B, temperature controlled
Placard: Flammable Solid. 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 3232
Class: 4
Placard type: Flammable Solid
ERG: Guide 150 (check current ERG)
Isolation: ERG 150: isolate spill 25m all directions; if tank/cargo involved in fire, isolate 800m all directions and consider evacuation; maintain temperature control to prevent runaway decomposition
Chemical & Response Details
| Also known as | Self-reactive solid Type BOrganic peroxide type solidTemperature-sensitive reactive solidSADT-controlled solid |
| Appearance | Solid material, appearance varies by specific formulation. These are temperature-sensitive organic compounds that can undergo vigorous exothermic decomposition. Typically stored and shipped under refrigeration. |
| Flash Point | Not applicable (self-reactive solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | No significant reaction with water, but water may not be effective for extinguishing fires involving these materials |
| Extinguishing | Dry chemical, CO2, water spray for cooling only; avoid direct water streams that may spread material |
| PPE | ⚠️ Level B minimum with SCBA required; full protective clothing; maintain strict temperature control during handling |
| Isolation | ERG 150: isolate spill 25m all directions; if tank/cargo involved in fire, isolate 800m all directions and consider evacuation; maintain temperature control to prevent runaway decomposition |
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
- 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.
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 3232 — Self-reactive solid type B, temperature HAZMAT RADIO NOTE — UN 3232
Product: Self-reactive solid type B, temperature controlled
Class 4 / Flammable Solid / ERG 150
PPE: Level B minimum with SCBA required; full protective clothing; maintain strict temperature control during handling
ISOLATION: ERG 150: isolate spill 25m all directions; if tank/cargo involved in fire, isolate 800m all directions and consider evacuation; maintain temperature control to prevent runaway decomposition
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 3232 — Self-reactive solid type B, temperature controlled
Class: 4 | Placard: Flammable Solid | ERG Guide: 150
Appearance: Solid material, appearance varies by specific formulation. These are temperature-sensitive organic compounds that can undergo vigorous exothermic decomposition. Typically stored and shipped under refrigeration.
Water Reactivity: No significant reaction with water, but water may not be effective for extinguishing fires involving these materials
Extinguishing: Dry chemical, CO2, water spray for cooling only; avoid direct water streams that may spread material
PPE: Level B minimum with SCBA required; full protective clothing; maintain strict temperature control during handling
Isolation: ERG 150: isolate spill 25m all directions; if tank/cargo involved in fire, isolate 800m all directions and consider evacuation; maintain temperature control to prevent runaway decomposition
— 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/3232 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3232 Self-reactive solid type B, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/3232SMS / 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/3232
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FAQ
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 required; full protective clothing; maintain strict temperature control during handling
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.