☣️ UN 3238 • CLASS 4
Self-reactive solid 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 3238
Class: 4
Placard type: Flammable Solid
ERG: Guide 150 (check current ERG)
Isolation: ERG 150: Initial isolation 50m in all directions; if fire or spill involves large quantities, isolate 800m in all directions and consider evacuation for 1600m downwind
Chemical & Response Details
| Also known as | Self-reactive solid type ETemperature controlled self-reactive solidOrganic peroxide type E solidSADT controlled solid |
| Appearance | Solid material that may vary in color from white to yellow or other colors depending on specific formulation. Generally odorless to slight chemical odor. Requires temperature control during transport and storage. |
| 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 decompose exothermically in presence of water and heat |
| Extinguishing | Dry chemical, CO2, or water spray if necessary; avoid high pressure water streams |
| PPE | ⚠️ Level B minimum with SCBA; full face protection and chemical-resistant suit required; thermal protection if fire involved |
| Isolation | ERG 150: Initial isolation 50m in all directions; if fire or spill involves large quantities, isolate 800m in all directions and consider evacuation for 1600m downwind |
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 3238 — Self-reactive solid type E, temperature HAZMAT RADIO NOTE — UN 3238
Product: Self-reactive solid type E, temperature controlled
Class 4 / Flammable Solid / ERG 150
PPE: Level B minimum with SCBA; full face protection and chemical-resistant suit required; thermal protection if fire involved
ISOLATION: ERG 150: Initial isolation 50m in all directions; if fire or spill involves large quantities, isolate 800m in all directions and consider evacuation for 1600m downwind
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 3238 — Self-reactive solid type E, temperature controlled
Class: 4 | Placard: Flammable Solid | ERG Guide: 150
Appearance: Solid material that may vary in color from white to yellow or other colors depending on specific formulation. Generally odorless to slight chemical odor. Requires temperature control during transport and storage.
Water Reactivity: Generally no significant reaction with water, but may decompose exothermically in presence of water and heat
Extinguishing: Dry chemical, CO2, or water spray if necessary; avoid high pressure water streams
PPE: Level B minimum with SCBA; full face protection and chemical-resistant suit required; thermal protection if fire involved
Isolation: ERG 150: Initial isolation 50m in all directions; if fire or spill involves large quantities, isolate 800m in all directions and consider evacuation for 1600m downwind
— 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/3238 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3238 Self-reactive solid type E, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/3238SMS / 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/3238
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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; full face protection and chemical-resistant suit required; thermal protection if fire involved
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.