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 At a Glance
UN 3103 (Organic peroxide type C, liquid) is listed as DOT Class 5 Organic Peroxide and is assigned to ERG Guide 146. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.