☣️ UN 3233 • CLASS 4

UN 3233 — Self-reactive liquid type C, temperature controlled

Placard: Flammable Solid. ERG Guide 150. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

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⚠️ Verification required: Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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.

UN 3233 is Self-reactive liquid type C, temperature controlled, a self-reactive type C liquid assigned to ERG Guide 150. Heat, contamination and confinement can trigger decomposition. It requires active temperature-control verification during incidents.

Hazard overview: HIGHER-HAZARD self-reactive type C liquid; heat, contamination, shock or confinement may cause violent decomposition. Loss of required control temperature can lead to runaway decomposition and pressure buildup. May ignite and burn violently; decomposition can continue without outside oxygen.

Response guidance: For UN 3233, isolate the area, keep heat/friction/shock/contamination away and use SCBA from a protected position. Confirm control temperature and cooling status immediately. Cool exposures if safe and follow SDS/ERG 150.

Firefighter training notes: Training for UN 3233 should emphasize self-accelerating decomposition, temperature/control-temperature checks, contamination avoidance, remote cooling, evacuation triggers and runoff control. Use ERG 150, SDS and local SOP.

Regulatory context: Self-reactive liquid type C, temperature controlled is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation, package type and jurisdiction; verify shipping papers, SDS and authority guidance.

Storage & handling: Self-reactive liquid type C, temperature controlled should be stored in approved compatible packages away from heat, sunlight, friction, shock, contamination, acids, bases, metals and reducing agents. Maintain required control temperature, refrigeration checks and emergency cooling arrangements.

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UN 3233 Quick Details

UN 3233
Product name: Self-reactive liquid type C, temperature controlled
DOT Class: 4
Placard type: Flammable Solid
ERG Guide: 150 (check current ERG)
Initial 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

Common Hazards of UN 3233

  • HIGHER-HAZARD self-reactive type C liquid; heat, contamination, shock or confinement may cause violent decomposition.
  • Loss of required control temperature can lead to runaway decomposition and pressure buildup.
  • May ignite and burn violently; decomposition can continue without outside oxygen.
  • Containers may rupture or explode if heated or if decomposition begins.
  • Contamination with acids, bases, metals, reducing agents or incompatible organics may increase instability.
  • Fire may produce large volumes of irritating, toxic and/or corrosive gases.
  • Runoff may carry reactive residue and contaminated decomposition products.
  • Control temperature, emergency temperature, SADT and refrigeration status must be verified immediately.

Chemical Identity & Physical Properties

Liquid material that varies in color and odor depending on specific formulation. Requires temperature control during storage and transport to prevent self-accelerating decomposition.

Also known asSelf-reactive liquid type CTemperature controlled self-reactive substanceOrganic peroxide type liquidSADT-controlled reactive liquid
AppearanceLiquid material that varies in color and odor depending on specific formulation. Requires temperature control during storage and transport to prevent self-accelerating decomposition.
Flash PointVaries by formulation, typically low flash point liquids requiring temperature control
Boiling PointVaries by specific formulation, decomposes before boiling point is reached
Vapor DensityVaries by formulation, typically heavier than air (>1)
Water ReactivityMay react with water depending on formulation; avoid water contact unless compatibility is confirmed
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 3233

Extinguishing Media

Use water spray/fog from a protected distance for cooling and exposure protection when compatible. Maintain temperature control and withdraw if containers heat or decomposition accelerates.

PPE Requirements

⚠️ Level B minimum with SCBA required; full chemical protective suit for spills; maintain safe distance due to decomposition hazard

Use positive-pressure SCBA, full protective clothing and distance/blast protection. Avoid contaminated PPE, friction, heat and direct contact with reactive residue.

Isolation & Evacuation

ERG 150: Isolate spill 50m all directions initially; if tank/rail car involved in fire isolate 800m and evacuate 1600m downwind; monitor temperature closely
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 150).

First Actions for a UN 3233 Incident

  • Call 911 and the emergency response number on the shipping paper, if available.
  • Keep unauthorized personnel away and establish incident command.
  • Stay upwind, uphill and upstream.
  • Keep heat, sparks, friction, shock and contamination away from the material.
  • Check control-temperature status immediately and request specialist support if cooling is lost.
  • Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
  • Do not touch damaged containers, spilled material or residue without proper training and PPE.
  • Prevent contaminated runoff, dust, liquid and decontamination waste from spreading.
  • Ventilate confined spaces only after monitoring and only if properly trained and equipped.
  • Use ERG Guide 150, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
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📋 Copy & Share Field Card

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.

SMS WhatsApp
=== 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: Use water spray/fog from a protected distance for cooling and exposure protection when compatible. Maintain temperature control and withdraw if containers heat or decomposition accelerates. 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 — • HIGHER-HAZARD self-reactive type C liquid; heat, contamination, shock or confinement may cause violent decomposition. • Loss of required control temperature can lead to runaway decomposition and pressure buildup. • May ignite and burn violently; decomposition can continue without outside oxygen. — First Actions — • Call 911 and the emergency response number on the shipping paper, if available. • Keep unauthorized personnel away and establish incident command. • Stay upwind, uphill and upstream. • Keep heat, sparks, friction, shock and contamination away from the material. SOURCE: allfirefighter.com/hazmat/un/self-reactive-liquid-type-un-3233 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN3233 Self-reactive liquid type C, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/self-reactive-liquid-type-un-3233SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS.

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/self-reactive-liquid-type-un-3233

Related UN Numbers in Class 4

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 3233

UN 3233 is Self-reactive liquid type C, temperature controlled, assigned to ERG Guide 150.

Yes. Self-reactive liquid type C, temperature controlled is assigned to Class 4.1 and may burn violently or decompose when heated or contaminated.

HIGHER-HAZARD self-reactive type C liquid; heat, contamination, shock or confinement may cause violent decomposition. Loss of required control temperature can lead to runaway decomposition and pressure buildup. May ignite and burn violently; decomposition can continue without outside oxygen.

Use positive-pressure SCBA, full protective clothing and distance/blast protection. Avoid contaminated PPE, friction, heat and direct contact with reactive residue.

Use water spray/fog from a protected distance for cooling and exposure protection when compatible. Maintain temperature control and withdraw if containers heat or decomposition accelerates.

Heat, contamination, shock, friction, confinement or incompatible materials can trigger self-accelerating decomposition.

Loss of control temperature can allow the material to approach self-accelerating decomposition and rupture containers.
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.