☣️ UN 2426 • CLASS 5
UN 2426 — Ammonium nitrate, liquid (hot concentrated solution)
Placard: Oxidizer. ERG Guide 140. 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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UN 2426 Quick Details
UN 2426
Product name: Ammonium nitrate, liquid (hot concentrated solution)
DOT Class: 5
Placard type: Oxidizer
ERG Guide: 140 (check current ERG)
Initial isolation: ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m downwind
Common Hazards of UN 2426
- These substances will accelerate burning when involved in a fire.
- Some may decompose explosively when heated or involved in a fire.
- May explode from heat or contamination.
- Some will react explosively with hydrocarbons (fuels).
- May ignite combustibles (wood, paper, oil, clothing, etc.).
- Containers may explode when heated.
- Runoff may create fire or explosion hazard.
- Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or
Chemical Identity & Physical Properties
| Also known as | Ammonium nitrate solutionNitric acid ammonium salt solutionAN solutionHot concentrated ammonium nitrate liquor |
| CAS Number | 6484-52-2 |
| Appearance | Clear to slightly yellow liquid with no odor or faint ammonia odor. Hot concentrated aqueous solution (typically 80-95% concentration) maintained above crystallization point. |
| Flash Point | Not applicable (non-flammable oxidizer) |
| Boiling Point | Approximately 100-120C (212-248F) depending on concentration |
| Vapor Density | Not applicable (low volatility liquid) |
| Water Reactivity | Miscible with water; dilution releases heat |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2426
Extinguishing Media
Water spray to cool containers; do not use foam on material itself
PPE Requirements
⚠️ Level B minimum with chemical-resistant suit; SCBA required; thermal protection if hot solution involved
Isolation & Evacuation
ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m downwind
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 140).
First Actions for a UN 2426 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
- Consider initial downwind evacuation for at least 100 meters (330 feet).
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📋 Copy & Share Field Card
UN 2426 — Ammonium nitrate, liquid (hot concentratHAZMAT RADIO NOTE — UN 2426
Product: Ammonium nitrate, liquid (hot concentrated solution)
Class 5 / Oxidizer / ERG 140
PPE: Level B minimum with chemical-resistant suit; SCBA required; thermal protection if hot solution involved
ISOLATION: ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m downwind
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 2426 — Ammonium nitrate, liquid (hot concentrated solution)
Class: 5 | Placard: Oxidizer | ERG Guide: 140
Appearance: Clear to slightly yellow liquid with no odor or faint ammonia odor. Hot concentrated aqueous solution (typically 80-95% concentration) maintained above crystallization point.
Water Reactivity: Miscible with water; dilution releases heat
Extinguishing: Water spray to cool containers; do not use foam on material itself
PPE: Level B minimum with chemical-resistant suit; SCBA required; thermal protection if hot solution involved
Isolation: ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m downwind
— Key Hazards —
• These substances will accelerate burning when involved in a fire.
• Some may decompose explosively when heated or involved in a fire.
• May explode from heat or contamination.
— 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/2426 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2426 Ammonium nitrate, liquid (hot concentrated solution) Cls5 ERG140 | allfirefighter.com/hazmat/un/2426SMS / 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/2426
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Frequently Asked Questions about UN 2426
These substances will accelerate burning when involved in a fire. Some may decompose explosively when heated or involved in a fire. May explode from heat or contamination. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing, etc.). Containers may explode when heated. Runoff may create fire or explosion hazard. Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or
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 chemical-resistant suit; SCBA required; thermal protection if hot solution involved
Water reactivity: Miscible with water; dilution releases heat. Recommended extinguishing: Water spray to cool containers; do not use foam on material itself.
ERG Guide 140 recommendation: ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m downwind
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 140 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.