☣️ UN 3370 • CLASS 4

Urea nitrate, wetted with not less than 10% water

Placard: Flammable Solid. 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 3370
Class: 4
Placard type: Flammable Solid
ERG: Guide 113 (check current ERG)
Isolation: ERG 113: Isolate spill 25m (80ft) all directions. For fire: isolate 800m (0.5 miles) initially in all directions, evacuate if tank/rail car involved.
Chemical & Response Details
Also known asUrea mononitrateCarbamide nitrateNitratoureaAcidulated urea
CAS Number124-47-0
AppearanceWhite to pale yellow crystalline solid or powder. Odorless or slight ammonia-like odor. Shipped as a wetted paste or slurry to reduce explosion hazard.
Flash PointNot applicable (oxidizing solid, not combustible itself but enhances combustion)
Boiling PointNot applicable (decomposes before boiling at approximately 152C/306F)
Vapor DensityNot applicable (solid)
Water ReactivitySoluble in water; no violent reaction. Water acts as desensitizer and prevents detonation.
ExtinguishingWater spray to keep containers cool; CO2, dry chemical for small fires. Do NOT dry out material.
PPE⚠️ Level B minimum with SCBA required. Full protective clothing and face shield. Avoid all contact with dried material.
IsolationERG 113: Isolate spill 25m (80ft) all directions. For fire: isolate 800m (0.5 miles) initially in all directions, evacuate if tank/rail car involved.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • Flammable/combustible material.
  • May be ignited by heat, sparks or flames.
  • DRIED OUT material may explode if exposed to heat, flame, friction or shock; treat as an
  • Keep material wet with water or treat as an explosive (GUIDE 112).
  • Runoff to sewer may create fire or explosion hazard.
  • Some are toxic and may be fatal if inhaled, ingested or absorbed through skin. Specifically,
  • Contact may cause burns to skin and eyes.
  • Fire may produce irritating, corrosive and/or toxic gases.
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 immediately for at least 100 meters (330 feet) in all directions.
  • Consider initial evacuation for 500 meters (1/3 mile) in all directions.
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UN 3370 — Urea nitrate, wetted with not less than
HAZMAT RADIO NOTE — UN 3370 Product: Urea nitrate, wetted with not less than 10% water Class 4 / Flammable Solid / ERG 113 PPE: Level B minimum with SCBA required. Full protective clothing and face shield. Avoid all contact with dried material. ISOLATION: ERG 113: Isolate spill 25m (80ft) all directions. For fire: isolate 800m (0.5 miles) initially in all directions, evacuate if tank/rail car involved. 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 3370 — Urea nitrate, wetted with not less than 10% water Class: 4 | Placard: Flammable Solid | ERG Guide: 113 Appearance: White to pale yellow crystalline solid or powder. Odorless or slight ammonia-like odor. Shipped as a wetted paste or slurry to reduce explosion hazard. Water Reactivity: Soluble in water; no violent reaction. Water acts as desensitizer and prevents detonation. Extinguishing: Water spray to keep containers cool; CO2, dry chemical for small fires. Do NOT dry out material. PPE: Level B minimum with SCBA required. Full protective clothing and face shield. Avoid all contact with dried material. Isolation: ERG 113: Isolate spill 25m (80ft) all directions. For fire: isolate 800m (0.5 miles) initially in all directions, evacuate if tank/rail car involved. — Key Hazards — • Flammable/combustible material. • May be ignited by heat, sparks or flames. • DRIED OUT material may explode if exposed to heat, flame, friction or shock; treat as an — 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/3370 | 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)
UN3370 Urea nitrate, wetted with not less than 10% water Cls4 ERG113 | allfirefighter.com/hazmat/un/3370SMS / 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/3370
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

Flammable/combustible material. May be ignited by heat, sparks or flames. DRIED OUT material may explode if exposed to heat, flame, friction or shock; treat as an Keep material wet with water or treat as an explosive (GUIDE 112). Runoff to sewer may create fire or explosion hazard. Some are toxic and may be fatal if inhaled, ingested or absorbed through skin. Specifically, Contact may cause burns to skin and eyes. Fire may produce irritating, corrosive and/or toxic gases.

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 SCBA required. Full protective clothing and face shield. Avoid all contact with dried material.

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 113 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.