☣️ UN 2741 • CLASS 5

Barium hypochlorite, with more than 22% available chlorine

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 2741
Class: 5
Placard type: Oxidizer
ERG: Guide 141 (check current ERG)
Isolation: ERG 141: isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation
Chemical & Response Details
Also known asBarium hypochloriteHypochlorous acid barium saltBarium chlorite hypochlorite
CAS Number13477-10-6
AppearanceWhite to grayish-white granular powder or solid with a chlorine-like odor. Oxidizing solid that decomposes in moist air.
Flash PointNot applicable (oxidizing solid, non-flammable but accelerates combustion)
Boiling PointNot applicable (decomposes before boiling)
Vapor DensityNot applicable (solid)
Water ReactivityDecomposes slowly in water, releasing oxygen and forming barium hydroxide; avoid large amounts of water
ExtinguishingDry chemical, sand, or dry earth; do not use water except in large flooding quantities; avoid organic materials
PPE⚠️ Level B minimum with full face SCBA; chemical-resistant suit; avoid skin contact due to oxidizer and caustic properties
IsolationERG 141: isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation
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 2741 — Barium hypochlorite, with more than 22%
HAZMAT RADIO NOTE — UN 2741 Product: Barium hypochlorite, with more than 22% available chlorine Class 5 / Oxidizer / ERG 141 PPE: Level B minimum with full face SCBA; chemical-resistant suit; avoid skin contact due to oxidizer and caustic properties ISOLATION: ERG 141: isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation 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 2741 — Barium hypochlorite, with more than 22% available chlorine Class: 5 | Placard: Oxidizer | ERG Guide: 141 Appearance: White to grayish-white granular powder or solid with a chlorine-like odor. Oxidizing solid that decomposes in moist air. Water Reactivity: Decomposes slowly in water, releasing oxygen and forming barium hydroxide; avoid large amounts of water Extinguishing: Dry chemical, sand, or dry earth; do not use water except in large flooding quantities; avoid organic materials PPE: Level B minimum with full face SCBA; chemical-resistant suit; avoid skin contact due to oxidizer and caustic properties Isolation: ERG 141: isolate 100m in all directions; if tank/rail car involved in fire, isolate 800m and consider evacuation — 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/2741 | 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)
UN2741 Barium hypochlorite, with more than 22% available chlorine Cls5 ERG141 | allfirefighter.com/hazmat/un/2741SMS / 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/2741
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 with full face SCBA; chemical-resistant suit; avoid skin contact due to oxidizer and caustic properties

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.