☣️ UN 3233 • CLASS 4
Self-reactive liquid type C, 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 3233
Class: 4
Placard type: Flammable Solid
ERG: Guide 150 (check current ERG)
Isolation: ERG 150: Isolate spill 50m all directions initially; if tank/rail car involved in fire isolate 800m and evacuate 1600m downwind; monitor temperature closely
Chemical & Response Details
| Also known as | Self-reactive liquid type CTemperature controlled self-reactive substanceOrganic peroxide type liquidSADT-controlled reactive liquid |
| Appearance | Liquid material that varies in color and odor depending on specific formulation. Requires temperature control during storage and transport to prevent self-accelerating decomposition. |
| Flash Point | Varies by formulation, typically low flash point liquids requiring temperature control |
| Boiling Point | Varies by specific formulation, decomposes before boiling point is reached |
| Vapor Density | Varies by formulation, typically heavier than air (>1) |
| Water Reactivity | May react with water depending on formulation; avoid water contact unless compatibility is confirmed |
| Extinguishing | Alcohol-resistant foam, dry chemical, CO2; avoid water streams which may spread material |
| PPE | ⚠️ Level B minimum with SCBA required; full chemical protective suit for spills; maintain safe distance due to decomposition hazard |
| Isolation | ERG 150: Isolate spill 50m all directions initially; if tank/rail car involved in fire isolate 800m and evacuate 1600m downwind; monitor temperature closely |
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 3233 — Self-reactive liquid type C, temperature HAZMAT RADIO NOTE — UN 3233
Product: Self-reactive liquid type C, temperature controlled
Class 4 / Flammable Solid / ERG 150
PPE: Level B minimum with SCBA required; full chemical protective suit for spills; maintain safe distance due to decomposition hazard
ISOLATION: ERG 150: Isolate spill 50m all directions initially; if tank/rail car involved in fire isolate 800m and evacuate 1600m downwind; monitor temperature closely
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 3233 — Self-reactive liquid type C, temperature controlled
Class: 4 | Placard: Flammable Solid | ERG Guide: 150
Appearance: Liquid material that varies in color and odor depending on specific formulation. Requires temperature control during storage and transport to prevent self-accelerating decomposition.
Water Reactivity: May react with water depending on formulation; avoid water contact unless compatibility is confirmed
Extinguishing: Alcohol-resistant foam, dry chemical, CO2; avoid water streams which may spread material
PPE: Level B minimum with SCBA required; full chemical protective suit for spills; maintain safe distance due to decomposition hazard
Isolation: ERG 150: Isolate spill 50m all directions initially; if tank/rail car involved in fire isolate 800m and evacuate 1600m downwind; monitor temperature closely
— 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/3233 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3233 Self-reactive liquid type C, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/3233SMS / 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/3233
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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 chemical protective suit for spills; maintain safe distance due to decomposition hazard
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.