☣️ UN 1463 • CLASS 5

Chromium trioxide, anhydrous

Placard: Oxidizer. 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 1463
Class: 5
Placard type: Oxidizer
ERG: Guide 141 (check current ERG)
Isolation: ERG 141: isolate spill area 50m in all directions; if fire or large spill, isolate 800m initially and evacuate downwind
Chemical & Response Details
Also known asChromic acid anhydrideChromium(VI) oxideChromic anhydrideChromium oxide
CAS Number1333-82-0
AppearanceDark purplish-red to brownish-red, odorless crystalline solid that is highly deliquescent (absorbs moisture from air).
Flash PointNot applicable (non-flammable oxidizer)
Boiling PointDecomposes at 250C (482F) before boiling
Vapor DensityNot applicable (solid)
Water ReactivityDissolves readily in water forming chromic acid solution; reaction is exothermic and may generate heat
ExtinguishingDry chemical, soda ash, lime; avoid organic materials and combustibles
PPE⚠️ Level B minimum; full face SCBA required; impervious chemical protective clothing; highly toxic and corrosive
IsolationERG 141: isolate spill area 50m in all directions; if fire or large spill, isolate 800m initially and evacuate downwind
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • These substances will accelerate burning when involved in a fire.
  • May explode from heat or contamination.
  • Some may burn rapidly.
  • 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.
  • Toxic by ingestion.
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 100 meters (330 feet).
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UN 1463 — Chromium trioxide, anhydrous
HAZMAT RADIO NOTE — UN 1463 Product: Chromium trioxide, anhydrous Class 5 / Oxidizer / ERG 141 PPE: Level B minimum; full face SCBA required; impervious chemical protective clothing; highly toxic and corrosive ISOLATION: ERG 141: isolate spill area 50m in all directions; if fire or large spill, isolate 800m initially and evacuate downwind 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 1463 — Chromium trioxide, anhydrous Class: 5 | Placard: Oxidizer | ERG Guide: 141 Appearance: Dark purplish-red to brownish-red, odorless crystalline solid that is highly deliquescent (absorbs moisture from air). Water Reactivity: Dissolves readily in water forming chromic acid solution; reaction is exothermic and may generate heat Extinguishing: Dry chemical, soda ash, lime; avoid organic materials and combustibles PPE: Level B minimum; full face SCBA required; impervious chemical protective clothing; highly toxic and corrosive Isolation: ERG 141: isolate spill area 50m in all directions; if fire or large spill, isolate 800m initially and evacuate downwind — Key Hazards — • These substances will accelerate burning when involved in a fire. • May explode from heat or contamination. • Some may burn rapidly. — 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/1463 | 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)
UN1463 Chromium trioxide, anhydrous Cls5 ERG141 | allfirefighter.com/hazmat/un/1463SMS / 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/1463
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

These substances will accelerate burning when involved in a fire. May explode from heat or contamination. Some may burn rapidly. 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. Toxic by ingestion.

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; full face SCBA required; impervious chemical protective clothing; highly toxic and corrosive

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 141 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.