☣️ UN 1807 • CLASS 8
Phosphorus pentoxide
Placard: Corrosive. 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 1807
Class: 8
Placard type: Corrosive
ERG: Guide 137 (check current ERG)
Isolation: ERG 137: Isolate spill area immediate 25-50m. For large spill consider initial evacuation 100m downwind. If fire, isolate 800m all directions.
Chemical & Response Details
| Also known as | Phosphoric anhydrideDiphosphorus pentoxidePhosphorus(V) oxidePhosphoric acid anhydride |
| CAS Number | 1314-56-3 |
| Appearance | White, odorless crystalline powder or granular solid. Hygroscopic, readily absorbs moisture from air forming phosphoric acid mist. |
| Flash Point | Not applicable (non-combustible solid) |
| Boiling Point | 360C (680F) sublimes |
| Vapor Density | Not applicable (solid) |
| 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. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- 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.
First actions (field-minded)
- 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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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.
=== 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.
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
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FAQ
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.
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.