☣️ UN 2846 • CLASS 4
UN 2846 — Pyrophoric solid, organic, n.o.s.
Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ 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.
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UN 2846 Quick Details
UN 2846
Product name: Pyrophoric solid, organic, n.o.s.
DOT Class: 4
Placard type: Spontaneously Combustible
ERG Guide: 135 (check current ERG)
Initial isolation: ERG 135: isolate spill area immediately for at least 25-50m in all directions; if fire or large spill, isolate 800m in all directions and consider evacuation for 800m downwind
Common Hazards of UN 2846
- Flammable/combustible material.
- May ignite on contact with moist air or moisture.
- May burn rapidly with flare-burning effect.
- Some react vigorously or explosively on contact with water.
- Some may decompose explosively when heated or involved in a fire.
- May re-ignite after fire is extinguished.
- Runoff may create fire or explosion hazard.
- Containers may explode when heated.
Chemical Identity & Physical Properties
| Also known as | Pyrophoric organic solidSelf-igniting organic solidSpontaneously combustible organic solidAir-reactive organic solid |
| Appearance | Typically a fine powder or granular solid that may vary in color from tan to dark brown or black. Often has little to no odor in its packaged state. Ignites spontaneously upon exposure to air at or below 54°C (130°F). |
| Flash Point | Not applicable (ignites spontaneously in air) |
| Boiling Point | Not applicable (decomposes upon ignition) |
| Vapor Density | Not applicable (solid material) |
| Water Reactivity | May react with water or moisture to generate flammable gases or increase ignitability; keep dry |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2846
Extinguishing Media
Dry sand, dry chemical, soda ash, lime; DO NOT use water, foam, or CO2
PPE Requirements
⚠️ Level B minimum with SCBA; full protective clothing and face shield required; avoid any static discharge or friction
Isolation & Evacuation
ERG 135: isolate spill area immediately for at least 25-50m in all directions; if fire or large spill, isolate 800m in all directions and consider evacuation for 800m downwind
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 135).
First Actions for a UN 2846 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Stay upwind, uphill and/or upstream.
- Keep unauthorized personnel away.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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UN 2846 — Pyrophoric solid, organic, n.o.s.HAZMAT RADIO NOTE — UN 2846
Product: Pyrophoric solid, organic, n.o.s.
Class 4 / Spontaneously Combustible / ERG 135
PPE: Level B minimum with SCBA; full protective clothing and face shield required; avoid any static discharge or friction
ISOLATION: ERG 135: isolate spill area immediately for at least 25-50m in all directions; if fire or large spill, isolate 800m in all directions and consider evacuation for 800m downwind
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 2846 — Pyrophoric solid, organic, n.o.s.
Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 135
Appearance: Typically a fine powder or granular solid that may vary in color from tan to dark brown or black. Often has little to no odor in its packaged state. Ignites spontaneously upon exposure to air at or below 54°C (130°F).
Water Reactivity: May react with water or moisture to generate flammable gases or increase ignitability; keep dry
Extinguishing: Dry sand, dry chemical, soda ash, lime; DO NOT use water, foam, or CO2
PPE: Level B minimum with SCBA; full protective clothing and face shield required; avoid any static discharge or friction
Isolation: ERG 135: isolate spill area immediately for at least 25-50m in all directions; if fire or large spill, isolate 800m in all directions and consider evacuation for 800m downwind
— Key Hazards —
• Flammable/combustible material.
• May ignite on contact with moist air or moisture.
• May burn rapidly with flare-burning effect.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Stay upwind, uphill and/or upstream.
• Keep unauthorized personnel away.
• Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
SOURCE: allfirefighter.com/hazmat/un/2846 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2846 Pyrophoric solid, organic, n.o.s. Cls4 ERG135 | allfirefighter.com/hazmat/un/2846SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/2846
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Frequently Asked Questions about UN 2846
Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Stay upwind, uphill and/or upstream. Keep unauthorized personnel away.
Level B minimum with SCBA; full protective clothing and face shield required; avoid any static discharge or friction
Water reactivity: May react with water or moisture to generate flammable gases or increase ignitability; keep dry. Recommended extinguishing: Dry sand, dry chemical, soda ash, lime; DO NOT use water, foam, or CO2.
ERG Guide 135 recommendation: ERG 135: isolate spill area immediately for at least 25-50m in all directions; if fire or large spill, isolate 800m in all directions and consider evacuation for 800m downwind
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 135 and your department SOP/SOG for incident-specific protective actions.
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.