☣️ UN 2447 • CLASS 4

Phosphorus, white, molten

Placard: Spontaneously Combustible. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

🚒☣️
⚠️ 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 2447
Class: 4
Placard type: Spontaneously Combustible
ERG: Guide 136 (check current ERG)
Isolation: ERG 136: Isolate spill area immediate 50m (150 ft) in all directions. For large spill, isolate 800m (0.5 mile) in all directions. Evacuate downwind area if fire.
Chemical & Response Details
Also known asWhite phosphorus moltenYellow phosphorus moltenP4 moltenTetraphosphorus molten
CAS Number12185-10-3
AppearanceTranslucent white to yellow waxy solid that becomes a colorless to yellow liquid when molten (above 44°C/111°F). Garlic-like odor. Pyrophoric material that ignites spontaneously in air.
Flash PointNot applicable (pyrophoric solid/liquid, ignites spontaneously in air at approximately 30°C/86°F)
Boiling Point280°C (536°F)
Vapor Density4.3 (heavier than air)
Water ReactivityNo significant reaction with water, but hydrolyzes slowly forming phosphine gas and phosphoric acid
ExtinguishingDry sand, soda ash, or dry chemical extinguishing agents. Do not use water or foam. Keep material submerged under water for storage.
PPE⚠️ Level A minimum for spill response; full encapsulating suit with SCBA required. Molten material causes severe thermal and chemical burns.
IsolationERG 136: Isolate spill area immediate 50m (150 ft) in all directions. For large spill, isolate 800m (0.5 mile) in all directions. Evacuate downwind area if fire.
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 2447 — Phosphorus, white, molten
HAZMAT RADIO NOTE — UN 2447 Product: Phosphorus, white, molten Class 4 / Spontaneously Combustible / ERG 136 PPE: Level A minimum for spill response; full encapsulating suit with SCBA required. Molten material causes severe thermal and chemical burns. ISOLATION: ERG 136: Isolate spill area immediate 50m (150 ft) in all directions. For large spill, isolate 800m (0.5 mile) in all directions. Evacuate downwind area if fire. 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 2447 — Phosphorus, white, molten Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 136 Appearance: Translucent white to yellow waxy solid that becomes a colorless to yellow liquid when molten (above 44°C/111°F). Garlic-like odor. Pyrophoric material that ignites spontaneously in air. Water Reactivity: No significant reaction with water, but hydrolyzes slowly forming phosphine gas and phosphoric acid Extinguishing: Dry sand, soda ash, or dry chemical extinguishing agents. Do not use water or foam. Keep material submerged under water for storage. PPE: Level A minimum for spill response; full encapsulating suit with SCBA required. Molten material causes severe thermal and chemical burns. Isolation: ERG 136: Isolate spill area immediate 50m (150 ft) in all directions. For large spill, isolate 800m (0.5 mile) in all directions. Evacuate downwind area if fire. — 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/2447 | 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)
UN2447 Phosphorus, white, molten Cls4 ERG136 | allfirefighter.com/hazmat/un/2447SMS / 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/2447
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 minimum for spill response; full encapsulating suit with SCBA required. Molten material causes severe thermal and chemical burns.

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.