☣️ 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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⚠️ 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 2846 is Pyrophoric solid, organic, n.o.s., a broad pyrophoric organic solid entry assigned to ERG Guide 135. Exact product/SDS must be verified before tactics.

Hazard overview: PYROPHORIC organic solid, n.o.s.; may ignite spontaneously on exposure to air. Exact product may also be water-reactive, toxic or solvent-wet; verify SDS and shipping papers. May re-ignite after apparent extinguishment.

Response guidance: For UN 2846, isolate the area, exclude water/moisture and use SCBA. Use only compatible dry media, watch for re-ignition and verify tactics with SDS and ERG 135.

Firefighter training notes: Training for UN 2846 should emphasize water/moisture exclusion, dry-media tactics, re-ignition checks, gas monitoring, SCBA use and runoff control. Use ERG 135, SDS and local SOP.

Regulatory context: Pyrophoric solid, organic, n.o.s. is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.

Storage & handling: Pyrophoric solid, organic, n.o.s. should be stored dry in sealed compatible containers away from water, moisture, acids, oxidizers and ignition sources. Keep compatible dry media available.

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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

  • PYROPHORIC organic solid, n.o.s.; may ignite spontaneously on exposure to air.
  • Exact product may also be water-reactive, toxic or solvent-wet; verify SDS and shipping papers.
  • May re-ignite after apparent extinguishment.
  • Water, foam or CO2 may worsen some pyrophoric reactions or spread burning material.
  • Fire may produce toxic organic smoke and irritating gases.
  • Runoff may carry reactive or toxic contamination.
  • Packaging condition strongly affects fire and spill behavior.

Chemical Identity & Physical Properties

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).

Also known asPyrophoric organic solidSelf-igniting organic solidSpontaneously combustible organic solidAir-reactive organic solid
AppearanceTypically 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 PointNot applicable (ignites spontaneously in air)
Boiling PointNot applicable (decomposes upon ignition)
Vapor DensityNot applicable (solid material)
Water ReactivityMay 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

Use dry powder, dry sand or SDS-approved media. Do not use water, foam or CO2 unless the SDS or incident command confirms compatibility.

PPE Requirements

⚠️ Level B minimum with SCBA; full protective clothing and face shield required; avoid any static discharge or friction

Use positive-pressure SCBA and dry compatible protective clothing. Protect against fire, caustic/reactive dust and toxic decomposition products; exclude moisture.

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 and the emergency response number on the shipping paper, if available.
  • Keep unauthorized personnel away and establish incident command.
  • Stay upwind, uphill and upstream.
  • Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
  • Keep water or moisture contact controlled because reaction or re-ignition hazards may be severe.
  • 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 135, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
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📋 Copy & Share Field Card

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.

SMS WhatsApp
=== 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: Use dry powder, dry sand or SDS-approved media. Do not use water, foam or CO2 unless the SDS or incident command confirms compatibility. 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 — • PYROPHORIC organic solid, n.o.s.; may ignite spontaneously on exposure to air. • Exact product may also be water-reactive, toxic or solvent-wet; verify SDS and shipping papers. • May re-ignite after apparent extinguishment. — First Actions — • 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. • Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact. SOURCE: allfirefighter.com/hazmat/un/pyrophoric-solid-organic-n-un-2846 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN2846 Pyrophoric solid, organic, n.o.s. Cls4 ERG135 | allfirefighter.com/hazmat/un/pyrophoric-solid-organic-n-un-2846SMS / 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/pyrophoric-solid-organic-n-un-2846

Related UN Numbers in Class 4

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 2846

UN 2846 is Pyrophoric solid, organic, n.o.s., assigned to ERG Guide 135.

Yes. Pyrophoric solid, organic, n.o.s. may ignite spontaneously in air; exact behavior depends on the product.

PYROPHORIC organic solid, n.o.s.; may ignite spontaneously on exposure to air. Exact product may also be water-reactive, toxic or solvent-wet; verify SDS and shipping papers. May re-ignite after apparent extinguishment.

Use positive-pressure SCBA and dry compatible protective clothing. Protect against fire, caustic/reactive dust and toxic decomposition products; exclude moisture.

Use dry powder, dry sand or SDS-approved media. Do not use water, foam or CO2 unless the SDS or incident command confirms compatibility.

This is a broad n.o.s. pyrophoric entry; toxicity, water reactivity and extinguishing media depend on the exact solid.

Yes. Pyrophoric residues may re-ignite when exposed to air, so overhaul requires specialist control.
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.