UN 3239 — Self-reactive liquid type F, temperature controlled
Placard: Flammable Solid. ERG Guide 150. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3239 is Self-reactive liquid type F, temperature controlled, a self-reactive type F liquid assigned to ERG Guide 150. Heat, contamination and confinement can trigger decomposition. It requires active temperature-control verification during incidents.
Hazard overview: Self-reactive type F liquid; generally lower than types B/C, but heating or contamination can still cause dangerous 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 3239, 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 3239 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 F, 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 F, 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.
UN 3239 Quick Details
Common Hazards of UN 3239
- Self-reactive type F liquid; generally lower than types B/C, but heating or contamination can still cause dangerous 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 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.
| Also known as | Self-reactive liquid type FOrganic peroxide type F liquidTemperature-controlled self-reactive substanceSelf-accelerating decomposition liquid |
| 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. |
| Flash Point | Varies by specific formulation; many are flammable with flash points below 23C (73F) |
| Boiling Point | Varies by specific formulation; typically 50-200C (122-392F) |
| Vapor Density | Varies by formulation; typically heavier than air (>1) |
| Water Reactivity | Generally no significant reaction with water, but water may not control decomposition; specific reactivity depends on formulation |
Fireground Response Guidance — UN 3239
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA, full protective clothing and distance/blast protection. Avoid contaminated PPE, friction, heat and direct contact with reactive residue.
Isolation & Evacuation
First Actions for a UN 3239 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.
📋 Copy & Share Field Card
UN 3239 — Self-reactive liquid type F, temperatureUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.