UN 3103 — Organic peroxide type C, liquid
Placard: Organic Peroxide. ERG Guide 146. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3103 is Organic peroxide type C, liquid, an organic peroxide entry assigned to ERG Guide 146. Heat, shock, friction and contamination can cause violent decomposition.
Hazard overview: More hazardous type C 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 3103, 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 3103 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 C, 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 C, liquid should be stored in approved peroxide-compatible containers away from heat, sunlight, friction, contamination, acids, bases, metals, reducing agents and combustibles.
UN 3103 Quick Details
Common Hazards of UN 3103
- More hazardous type C 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 formulation; typically clear to pale yellow liquid with mild characteristic odor. Organic peroxides are thermally unstable oxidizing agents at room temperature.
| Also known as | Organic peroxide type C liquidClass 5.2 organic peroxidePeroxidic compound liquidType C peroxide formulation |
| Appearance | Varies by specific formulation; typically clear to pale yellow liquid with mild characteristic odor. Organic peroxides are thermally unstable oxidizing agents at room temperature. |
| Flash Point | Varies by formulation, typically 50-80°C (122-176°F) for Type C |
| Boiling Point | Varies by formulation, typically 100-200°C (212-392°F) |
| Vapor Density | Typically 3-6 (heavier than air, varies by specific peroxide) |
| Water Reactivity | Generally no violent reaction with water, but may decompose; some formulations may be water-reactive depending on composition |
Fireground Response Guidance — UN 3103
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 3103 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 3103 — Organic peroxide type C, 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.