☣️ UN 3404 • CLASS 4

Potassium sodium alloys, solid

Placard: Dangerous When Wet. 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 3404
Class: 4
Placard type: Dangerous When Wet
ERG: Guide 138 (check current ERG)
Verify shipping papers and exact product details; use ERG Guide 138 for initial actions and isolation/evacuation guidance.
Common hazards (high level)
  • Produce flammable gases on contact with water.
  • May ignite on contact with water or moist air.
  • Some react vigorously or explosively on contact with water.
  • May be ignited by heat, sparks or flames.
  • May re-ignite after fire is extinguished.
  • Some are transported in highly flammable liquids.
  • Runoff may create fire or explosion hazard.
  • Inhalation or contact with vapors, substance or decomposition products may cause severe injury or
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
  • Consider initial downwind evacuation for at least 300 meters (1000 feet).
Related UN numbers (same class)
This is a discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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MAYDAY / HAZMAT QUICK NOTE
UN 3404 — Potassium sodium alloys, solid
Class: 4 | Placard: Dangerous When Wet
ERG: Guide 138 (check current ERG)
FIRST ACTIONS: use SOP/SOG + ERG; stage upwind; isolate; deny entry; request Hazmat.
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FAQ

A UN/NA number is a four-digit identifier used in transport markings and placards to help identify hazardous materials for emergency response.

No. This page is a training/quick-reference aid. Always consult the current ERG and follow your SOP/SOG for incident-specific protective actions.

Common locations include placards, orange panels, shipping papers, SDS documents, container markings, rail car/vehicle IDs, and facility signage.
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.