☣️ UN 1807 • CLASS 8

UN 1807 — Phosphorus pentoxide

Placard: Corrosive. ERG Guide 137. 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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UN 1807 Quick Details

UN 1807
Product name: Phosphorus pentoxide
DOT Class: 8
Placard type: Corrosive
ERG Guide: 137 (check current ERG)
Initial isolation: ERG 137: Isolate spill area immediate 25-50m. For large spill consider initial evacuation 100m downwind. If fire, isolate 800m all directions.

Common Hazards of UN 1807

  • CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
  • Fire will produce irritating, corrosive and/or toxic gases.
  • Reaction with water may generate much heat that will increase the concentration of fumes in the air.
  • Contact with molten substance may cause severe burns to skin and eyes.
  • Runoff from fire control or dilution water may cause environmental contamination.
  • EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may
  • May ignite combustibles (wood, paper, oil, clothing, etc.).
  • Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff.

Chemical Identity & Physical Properties

Also known asPhosphoric anhydrideDiphosphorus pentoxidePhosphorus(V) oxidePhosphoric acid anhydride
CAS Number1314-56-3
AppearanceWhite, odorless crystalline powder or granular solid. Hygroscopic, readily absorbs moisture from air forming phosphoric acid mist.
Flash PointNot applicable (non-combustible solid)
Boiling Point360C (680F) sublimes
Vapor DensityNot applicable (solid)
Water ReactivityReacts violently with water generating intense heat and forming corrosive phosphoric acid. Keep dry, do not use water directly.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 1807

Extinguishing Media

Dry sand, soda ash, lime. No water or foam. CO2 may be used on surrounding fires but not directly on material.

PPE Requirements

⚠️ Level B minimum with full face SCBA. Chemical resistant suit, gloves, and boots. Respiratory protection mandatory due to corrosive mist formation.

Isolation & Evacuation

ERG 137: Isolate spill area immediate 25-50m. For large spill consider initial evacuation 100m downwind. If fire, isolate 800m all directions.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 137).

First Actions for a UN 1807 Incident

  • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
  • Keep unauthorized personnel away.
  • Stay upwind, uphill and/or upstream.
  • Ventilate closed spaces before entering, but only if properly trained and equipped.
  • 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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📋 Copy & Share Field Card

UN 1807 — Phosphorus pentoxide
HAZMAT RADIO NOTE — UN 1807 Product: Phosphorus pentoxide Class 8 / Corrosive / ERG 137 PPE: Level B minimum with full face SCBA. Chemical resistant suit, gloves, and boots. Respiratory protection mandatory due to corrosive mist formation. ISOLATION: ERG 137: Isolate spill area immediate 25-50m. For large spill consider initial evacuation 100m downwind. If fire, isolate 800m 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 1807 — Phosphorus pentoxide Class: 8 | Placard: Corrosive | ERG Guide: 137 Appearance: White, odorless crystalline powder or granular solid. Hygroscopic, readily absorbs moisture from air forming phosphoric acid mist. Water Reactivity: Reacts violently with water generating intense heat and forming corrosive phosphoric acid. Keep dry, do not use water directly. Extinguishing: Dry sand, soda ash, lime. No water or foam. CO2 may be used on surrounding fires but not directly on material. PPE: Level B minimum with full face SCBA. Chemical resistant suit, gloves, and boots. Respiratory protection mandatory due to corrosive mist formation. Isolation: ERG 137: Isolate spill area immediate 25-50m. For large spill consider initial evacuation 100m downwind. If fire, isolate 800m all directions. — Key Hazards — • CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance • Fire will produce irritating, corrosive and/or toxic gases. • Reaction with water may generate much heat that will increase the concentration of fumes in the air. — First Actions — • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper • Keep unauthorized personnel away. • Stay upwind, uphill and/or upstream. • Ventilate closed spaces before entering, but only if properly trained and equipped. SOURCE: allfirefighter.com/hazmat/un/1807 | 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)
UN1807 Phosphorus pentoxide Cls8 ERG137 | ERG 137: Isolate spill area immediate 25-50m. For large spill consider initial e | allfirefighter.com/hazmat/un/1807SMS / 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/1807

Related UN Numbers in Class 8

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 1807

CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance Fire will produce irritating, corrosive and/or toxic gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control or dilution water may cause environmental contamination. EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may May ignite combustibles (wood, paper, oil, clothing, etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff.

CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.

Level B minimum with full face SCBA. Chemical resistant suit, gloves, and boots. Respiratory protection mandatory due to corrosive mist formation.

Water reactivity: Reacts violently with water generating intense heat and forming corrosive phosphoric acid. Keep dry, do not use water directly.. Recommended extinguishing: Dry sand, soda ash, lime. No water or foam. CO2 may be used on surrounding fires but not directly on material..

ERG Guide 137 recommendation: ERG 137: Isolate spill area immediate 25-50m. For large spill consider initial evacuation 100m downwind. If fire, isolate 800m all directions.

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 137 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.