UN 3101 — Organic peroxide type B, liquid
Placard: Organic Peroxide. ERG Guide 146. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3101 is Organic peroxide type B, liquid, an organic peroxide entry assigned to ERG Guide 146. Heat, shock, friction and contamination can cause violent decomposition.
Hazard overview: More hazardous type B organic peroxide liquid; heat, contamination, friction or shock may cause violent decomposition or explosion. May burn rapidly with a flare effect and may ignite nearby combustibles. Containers may rupture or explode when heated or if decomposition starts.
Response guidance: For UN 3101, isolate widely, keep heat/shock/friction/contamination away and cool exposed containers from protection if safe. Follow SDS temperature limits and ERG 146.
Firefighter training notes: Training for UN 3101 should emphasize organic peroxide instability, SADT/control temperature, contamination avoidance, remote cooling, evacuation triggers and runoff control. Use ERG 146, SDS and local SOP.
Regulatory context: Organic peroxide type B, liquid is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation, temperature-control status and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Organic peroxide type B, liquid should be stored in approved peroxide-compatible containers away from heat, sunlight, friction, contamination, acids, bases, metals, reducing agents and combustibles.
UN 3101 Quick Details
Common Hazards of UN 3101
- More hazardous type B organic peroxide liquid; heat, contamination, friction or shock may cause violent decomposition or explosion.
- May burn rapidly with a flare effect and may ignite nearby combustibles.
- Containers may rupture or explode when heated or if decomposition starts.
- Contamination with acids, bases, metals, reducing agents or organic material can increase instability.
- Fire may produce irritating, corrosive and toxic gases.
- Runoff may carry reactive peroxide contamination.
- Exact formulation, dilution, control temperature and emergency temperature must be verified from SDS and shipping papers.
Chemical Identity & Physical Properties
Varies by specific compound; typically clear to colored liquid with mild or characteristic odor. Highly unstable organic peroxide formulation at room temperature.
| Also known as | Organic peroxide type B liquidClass 5.2 organic peroxideExplosive organic peroxide liquidSelf-reactive peroxide |
| Appearance | Varies by specific compound; typically clear to colored liquid with mild or characteristic odor. Highly unstable organic peroxide formulation at room temperature. |
| Flash Point | Varies by formulation; typically low flash point or may ignite spontaneously |
| Boiling Point | Varies by specific peroxide compound; may decompose before boiling |
| Vapor Density | Varies by compound; typically heavier than air (>1) |
| Water Reactivity | Generally no violent reaction with water, but may be incompatible with certain formulations; avoid contamination |
Fireground Response Guidance — UN 3101
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA, chemical-resistant protective clothing and distance/blast protection. Avoid contaminated PPE, friction, heat and direct contact.
Isolation & Evacuation
First Actions for a UN 3101 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.
- Eliminate ignition sources and keep heat, friction, shock and contamination away from the material.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 146, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3101 — Organic peroxide type B, liquidUse 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.