☣️ UN 3185 • CLASS 4

Self-heating liquid, corrosive, organic, n.o.s.

Placard: Spontaneously Combustible. 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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Quick details
UN 3185
Class: 4
Placard type: Spontaneously Combustible
ERG: Guide 136 (check current ERG)
Isolation: ERG 136: isolate spill area at least 25m in all directions; evacuate immediate area; if fire involves tank/rail car, isolate 800m and consider evacuation for 1600m in all directions
Chemical & Response Details
Also known asSelf-heating corrosive liquidSpontaneously heating liquid corrosive organicPyrophoric corrosive liquid organic
AppearanceVariable appearance depending on specific substance; typically a liquid at ambient or elevated temperature that may spontaneously heat when exposed to air. Often corrosive with irritating properties.
Flash PointNot applicable (self-heating/pyrophoric material)
Boiling PointVariable depending on specific chemical composition
Vapor DensityVariable, typically heavier than air
Water ReactivityMay react with water generating heat and corrosive vapors; use water with extreme caution
ExtinguishingDry chemical, CO2, or dry sand preferred; avoid water-based agents unless specifically compatible
PPE⚠️ Level A or B required; full face SCBA mandatory; chemical-resistant suit due to corrosive nature; avoid skin contact
IsolationERG 136: isolate spill area at least 25m in all directions; evacuate immediate area; if fire involves tank/rail car, isolate 800m and consider evacuation for 1600m in all directions
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • Extremely flammable; will ignite itself if exposed to air.
  • Burns rapidly, releasing dense, white, irritating fumes.
  • Substance may be transported in a molten form.
  • May re-ignite after fire is extinguished.
  • Corrosives in contact with metals may evolve flammable hydrogen gas.
  • Containers may explode when heated.
  • Fire will produce irritating, corrosive and/or toxic gases.
  • TOXIC and/or CORROSIVE; ingestion of substance or inhalation of decomposition products will cause
First actions (field-minded)
  • 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 3185 — Self-heating liquid, corrosive, organic,
HAZMAT RADIO NOTE — UN 3185 Product: Self-heating liquid, corrosive, organic, n.o.s. Class 4 / Spontaneously Combustible / ERG 136 PPE: Level A or B required; full face SCBA mandatory; chemical-resistant suit due to corrosive nature; avoid skin contact ISOLATION: ERG 136: isolate spill area at least 25m in all directions; evacuate immediate area; if fire involves tank/rail car, isolate 800m and consider evacuation for 1600m in all directions 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 3185 — Self-heating liquid, corrosive, organic, n.o.s. Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 136 Appearance: Variable appearance depending on specific substance; typically a liquid at ambient or elevated temperature that may spontaneously heat when exposed to air. Often corrosive with irritating properties. Water Reactivity: May react with water generating heat and corrosive vapors; use water with extreme caution Extinguishing: Dry chemical, CO2, or dry sand preferred; avoid water-based agents unless specifically compatible PPE: Level A or B required; full face SCBA mandatory; chemical-resistant suit due to corrosive nature; avoid skin contact Isolation: ERG 136: isolate spill area at least 25m in all directions; evacuate immediate area; if fire involves tank/rail car, isolate 800m and consider evacuation for 1600m in all directions — Key Hazards — • Extremely flammable; will ignite itself if exposed to air. • Burns rapidly, releasing dense, white, irritating fumes. • Substance may be transported in a molten form. — 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/3185 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN3185 Self-heating liquid, corrosive, organic, n.o.s. Cls4 ERG136 | allfirefighter.com/hazmat/un/3185SMS / 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/3185
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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FAQ

Extremely flammable; will ignite itself if exposed to air. Burns rapidly, releasing dense, white, irritating fumes. Substance may be transported in a molten form. May re-ignite after fire is extinguished. Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Fire will produce irritating, corrosive and/or toxic gases. TOXIC and/or CORROSIVE; ingestion of substance or inhalation of decomposition products will cause

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 A or B required; full face SCBA mandatory; chemical-resistant suit due to corrosive nature; avoid skin contact

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 136 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.