☣️ UN 3234 • CLASS 4

Self-reactive solid type C, temperature controlled

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

🚒☣️
⚠️ 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.
Advertisement
Quick details
UN 3234
Class: 4
Placard type: Flammable Solid
ERG: Guide 150 (check current ERG)
Isolation: ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins
Chemical & Response Details
Also known asSelf-reactive solid type CTemperature controlled organic peroxideSelf-accelerating decomposition materialSADT organic solid
AppearanceSolid material of varying color depending on specific compound; may be crystalline, powder, or granular form at room temperature; requires temperature control during transport and storage.
Flash PointNot applicable (self-reactive solid - decomposition rather than ignition)
Boiling PointNot applicable (decomposes before boiling)
Vapor DensityNot applicable (solid)
Water ReactivityVaries by specific compound; generally no violent reaction with water but may contaminate runoff
ExtinguishingDry chemical, CO2, water spray for cooling only; avoid materials that may accelerate decomposition
PPE⚠️ Level B minimum with SCBA; full structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously
IsolationERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins
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.
Advertisement
📋 Copy & Share
UN 3234 — Self-reactive solid type C, temperature
HAZMAT RADIO NOTE — UN 3234 Product: Self-reactive solid type C, temperature controlled Class 4 / Flammable Solid / ERG 150 PPE: Level B minimum with SCBA; full structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously ISOLATION: ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins 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 3234 — Self-reactive solid type C, temperature controlled Class: 4 | Placard: Flammable Solid | ERG Guide: 150 Appearance: Solid material of varying color depending on specific compound; may be crystalline, powder, or granular form at room temperature; requires temperature control during transport and storage. Water Reactivity: Varies by specific compound; generally no violent reaction with water but may contaminate runoff Extinguishing: Dry chemical, CO2, water spray for cooling only; avoid materials that may accelerate decomposition PPE: Level B minimum with SCBA; full structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously Isolation: ERG 150: Initial isolation 100m in all directions; protective action distance 300m downwind during fire; maintain control temperature; evacuate immediate area if decomposition begins — 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/3234 | 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)
UN3234 Self-reactive solid type C, temperature controlled Cls4 ERG150 | allfirefighter.com/hazmat/un/3234SMS / 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/3234
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
Advertisement

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 structural firefighter protective clothing; thermal protection recommended; monitor control temperature continuously

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.