☣️ UN 3239 • CLASS 4

Self-reactive liquid type F, 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 3239
Class: 4
Placard type: Flammable Solid
ERG: Guide 150 (check current ERG)
Isolation: ERG 150: Initial isolation 50m all directions; Protective action distance 100m downwind day, 200m night for small spills; maintain control temperature at all times during incident
Chemical & Response Details
Also known asSelf-reactive liquid type FOrganic peroxide type F liquidTemperature-controlled self-reactive substanceSelf-accelerating decomposition liquid
AppearanceLiquid form of organic compound or mixture that may vary in color from clear to colored; odor varies depending on specific composition; requires temperature control to prevent self-accelerating decomposition.
Flash PointVaries by specific formulation; many are flammable with flash points below 23C (73F)
Boiling PointVaries by specific formulation; typically 50-200C (122-392F)
Vapor DensityVaries by formulation; typically heavier than air (>1)
Water ReactivityGenerally no significant reaction with water, but water may not control decomposition; specific reactivity depends on formulation
ExtinguishingAlcohol-resistant foam, CO2, dry chemical; flooding quantities of water may be used to cool containers
PPE⚠️ Level B minimum recommended; SCBA required; thermal protective clothing if fire involved; maintain strict temperature control during handling
IsolationERG 150: Initial isolation 50m all directions; Protective action distance 100m downwind day, 200m night for small spills; maintain control temperature at all times during incident
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 3239 — Self-reactive liquid type F, temperature
HAZMAT RADIO NOTE — UN 3239 Product: Self-reactive liquid type F, temperature controlled Class 4 / Flammable Solid / ERG 150 PPE: Level B minimum recommended; SCBA required; thermal protective clothing if fire involved; maintain strict temperature control during handling ISOLATION: ERG 150: Initial isolation 50m all directions; Protective action distance 100m downwind day, 200m night for small spills; maintain control temperature at all times during incident ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 3239 — Self-reactive liquid type F, temperature controlled Class: 4 | Placard: Flammable Solid | ERG Guide: 150 Appearance: Liquid form of organic compound or mixture that may vary in color from clear to colored; odor varies depending on specific composition; requires temperature control to prevent self-accelerating decomposition. Water Reactivity: Generally no significant reaction with water, but water may not control decomposition; specific reactivity depends on formulation Extinguishing: Alcohol-resistant foam, CO2, dry chemical; flooding quantities of water may be used to cool containers PPE: Level B minimum recommended; SCBA required; thermal protective clothing if fire involved; maintain strict temperature control during handling Isolation: ERG 150: Initial isolation 50m all directions; Protective action distance 100m downwind day, 200m night for small spills; maintain control temperature at all times during incident — 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/3239 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN3239 Self-reactive liquid type F, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/3239SMS / 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/3239
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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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 recommended; SCBA required; thermal protective clothing if fire involved; 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.