☣️ UN 3237 • CLASS 4
Self-reactive liquid type E, 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 3237
Class: 4
Placard type: Flammable Solid
ERG: Guide 150 (check current ERG)
Isolation: ERG 150: Initial isolation 50m in all directions; Protective action distance 0.3km daytime, 0.5km nighttime for large spill; Critical to maintain control temperature below SADT threshold
Chemical & Response Details
| Also known as | Self-reactive liquid type ETemperature controlled self-reactive liquidOrganic peroxide type liquidSADT liquid type E |
| Appearance | Liquid organic compound requiring temperature control during transport. Appearance and odor vary depending on specific formulation, as this is a generic UN designation covering multiple chemical compositions. |
| Flash Point | Varies by formulation, typically low flash point |
| Boiling Point | Varies by formulation |
| Vapor Density | Varies by formulation, generally heavier than air |
| Water Reactivity | Typically no significant water reaction, but may contaminate water with reactive organic compounds |
| Extinguishing | Alcohol-resistant foam, dry chemical, CO2; avoid water streams that may spread material |
| PPE | ⚠️ Level B minimum with SCBA required; thermal protective clothing if fire involved; maintain temperature control to prevent self-accelerating decomposition |
| Isolation | ERG 150: Initial isolation 50m in all directions; Protective action distance 0.3km daytime, 0.5km nighttime for large spill; Critical to maintain control temperature below SADT threshold |
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 3237 — Self-reactive liquid type E, temperature HAZMAT RADIO NOTE — UN 3237
Product: Self-reactive liquid type E, temperature controlled
Class 4 / Flammable Solid / ERG 150
PPE: Level B minimum with SCBA required; thermal protective clothing if fire involved; maintain temperature control to prevent self-accelerating decomposition
ISOLATION: ERG 150: Initial isolation 50m in all directions; Protective action distance 0.3km daytime, 0.5km nighttime for large spill; Critical to maintain control temperature below SADT threshold
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 3237 — Self-reactive liquid type E, temperature controlled
Class: 4 | Placard: Flammable Solid | ERG Guide: 150
Appearance: Liquid organic compound requiring temperature control during transport. Appearance and odor vary depending on specific formulation, as this is a generic UN designation covering multiple chemical compositions.
Water Reactivity: Typically no significant water reaction, but may contaminate water with reactive organic compounds
Extinguishing: Alcohol-resistant foam, dry chemical, CO2; avoid water streams that may spread material
PPE: Level B minimum with SCBA required; thermal protective clothing if fire involved; maintain temperature control to prevent self-accelerating decomposition
Isolation: ERG 150: Initial isolation 50m in all directions; Protective action distance 0.3km daytime, 0.5km nighttime for large spill; Critical to maintain control temperature below SADT threshold
— 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/3237 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3237 Self-reactive liquid type E, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/3237SMS / 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/3237
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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; thermal protective clothing if fire involved; maintain temperature control to prevent self-accelerating decomposition
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.