☣️ UN 3545 • CLASS 5
UN 3545 — Articles containing organic peroxide, n.o.s.
Placard: Organic Peroxide. ERG Guide 145. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ Verification required:
Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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.
UN 3545 is Articles containing organic peroxide, n.o.s., assigned to ERG Guide 145. This entry should be verified with shipping papers, labels and the SDS before responders commit to close-range action.
Hazard overview: Articles containing organic peroxide, n.o.s. can intensify fire and may react dangerously with heat, contamination, fuels or damaged packaging. Containers or articles may rupture when heated.
Response guidance: Use ERG Guide 145, confirm the exact contents, isolate the area, keep unauthorized personnel away, control ignition sources and choose extinguishing agents based on the article or material involved.
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UN 3545 Quick Details
UN 3545
Product name: Articles containing organic peroxide, n.o.s.
DOT Class: 5
Placard type: Organic Peroxide
ERG Guide: 145 (check current ERG)
Initial isolation: ERG 145: isolate spill/leak area immediate 25m in all directions; if fire or large spill, isolate 800m in all directions; evacuate 800m in all directions if tank/railcar involved in fire
Common Hazards of UN 3545
- May explode from heat or contamination.
- May ignite combustibles (wood, paper, oil, clothing, etc.).
- May be ignited by heat, sparks or flames.
- May burn rapidly with flare-burning effect.
- Containers may explode when heated.
- Runoff may create fire or explosion hazard.
- Fire may produce irritating, corrosive and/or toxic gases.
- Ingestion or contact (skin, eyes) with substance may cause severe injury or burns.
Chemical Identity & Physical Properties
Solid articles or devices containing organic peroxide formulations. Physical form varies widely depending on the article; may be white, colored, or transparent solids or semi-solids embedded in various materials.
| Also known as | Organic peroxide-containing articlesArticles with organic peroxidePeroxide-impregnated articlesN.O.S. organic peroxide articles |
| Appearance | Solid articles or devices containing organic peroxide formulations. Physical form varies widely depending on the article; may be white, colored, or transparent solids or semi-solids embedded in various materials. |
| Flash Point | Not applicable (article-based material, flash point depends on peroxide type) |
| Boiling Point | Not applicable (solid article) |
| Vapor Density | Not applicable (solid article) |
| Water Reactivity | Generally no significant reaction with water, but avoid water on heated or burning material |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3545
Extinguishing Media
Dry chemical, sand, CO2; avoid water spray on heated material; cool containers with water from distance
PPE Requirements
⚠️ Level B minimum recommended; SCBA required in fire or decomposition scenarios; heat-resistant protective clothing if approaching heated articles
Level B minimum recommended; SCBA required in fire or decomposition scenarios; heat-resistant protective clothing if approaching heated articles. Select final PPE using ERG guidance, SDS, monitoring and incident command.
Isolation & Evacuation
ERG 145: isolate spill/leak area immediate 25m in all directions; if fire or large spill, isolate 800m in all directions; evacuate 800m in all directions if tank/railcar involved in fire
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 145).
First Actions for a UN 3545 Incident
- 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.
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📋 Copy & Share Field Card
UN 3545 — Articles containing organic peroxide, n.HAZMAT RADIO NOTE — UN 3545
Product: Articles containing organic peroxide, n.o.s.
Class 5 / Organic Peroxide / ERG 145
PPE: Level B minimum recommended; SCBA required in fire or decomposition scenarios; heat-resistant protective clothing if approaching heated articles
ISOLATION: ERG 145: isolate spill/leak area immediate 25m in all directions; if fire or large spill, isolate 800m in all directions; evacuate 800m in all directions if tank/railcar involved in fire
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 3545 — Articles containing organic peroxide, n.o.s.
Class: 5 | Placard: Organic Peroxide | ERG Guide: 145
Appearance: Solid articles or devices containing organic peroxide formulations. Physical form varies widely depending on the article; may be white, colored, or transparent solids or semi-solids embedded in various materials.
Water Reactivity: Generally no significant reaction with water, but avoid water on heated or burning material
Extinguishing: Dry chemical, sand, CO2; avoid water spray on heated material; cool containers with water from distance
PPE: Level B minimum recommended; SCBA required in fire or decomposition scenarios; heat-resistant protective clothing if approaching heated articles
Isolation: ERG 145: isolate spill/leak area immediate 25m in all directions; if fire or large spill, isolate 800m in all directions; evacuate 800m in all directions if tank/railcar involved in fire
— Key Hazards —
• May explode from heat or contamination.
• May ignite combustibles (wood, paper, oil, clothing, etc.).
• May be ignited by heat, sparks or flames.
— First Actions —
• 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.
SOURCE: allfirefighter.com/hazmat/un/articles-containing-organic-peroxide-un-3545 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3545 Articles containing organic peroxide, n.o.s. Cls5 ERG145 | allfirefighter.com/hazmat/un/articles-containing-organic-peroxide-un-3545SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/articles-containing-organic-peroxide-un-3545
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Frequently Asked Questions about UN 3545
UN 3545 is Articles containing organic peroxide, n.o.s., assigned to ERG Guide 145.
ERG Guide 145 applies for initial isolation, protective actions and first response guidance.
Articles containing organic peroxide, n.
Level B minimum recommended; SCBA required in fire or decomposition scenarios; heat-resistant protective clothing if approaching heated articles.
ERG 145: isolate spill/leak area immediate 25m in all directions; if fire or large spill, isolate 800m in all directions; evacuate 800m in all directions if tank/railcar involved in fire.
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.