☣️ UN 3149 • CLASS 5

Hydrogen peroxide and peroxyacetic acid mixture, with acid(s), water and not more than 5% peroxyacetic acid, stabilized

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 3149
Class: 5
Placard type: Oxidizer
ERG: Guide 140 (check current ERG)
Isolation: ERG 140: isolate spill 25-50m; evacuate 100m if large spill; 800m downwind for major fire
Chemical & Response Details
Also known asHydrogen peroxide-peroxyacetic acid mixturePeracetic acid-hydrogen peroxide solutionPAA-H2O2 mixtureStabilized peroxide-peracid blend
AppearanceClear to pale yellow liquid with a pungent, vinegar-like odor. Corrosive aqueous solution containing oxidizing agents.
Flash PointNot applicable (non-flammable oxidizer)
Boiling PointApproximately 100-110C (212-230F), varies with concentration
Vapor DensityGreater than 1 (heavier than air)
Water ReactivityMiscible with water; dilution reduces reactivity but generates heat
ExtinguishingWater spray, dry chemical, CO2; avoid organic materials and combustibles
PPE⚠️ Level B minimum; SCBA required; chemical-resistant suit, gloves, and face shield for corrosive liquid protection
IsolationERG 140: isolate spill 25-50m; evacuate 100m if large spill; 800m downwind for major fire
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.
  • 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
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 3149 — Hydrogen peroxide and peroxyacetic acid
HAZMAT RADIO NOTE — UN 3149 Product: Hydrogen peroxide and peroxyacetic acid mixture, with acid(s), water and not more than 5% peroxyacetic acid, stabilized Class 5 / Oxidizer / ERG 140 PPE: Level B minimum; SCBA required; chemical-resistant suit, gloves, and face shield for corrosive liquid protection ISOLATION: ERG 140: isolate spill 25-50m; evacuate 100m if large spill; 800m downwind for major fire 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 3149 — Hydrogen peroxide and peroxyacetic acid mixture, with acid(s), water and not more than 5% peroxyacetic acid, stabilized Class: 5 | Placard: Oxidizer | ERG Guide: 140 Appearance: Clear to pale yellow liquid with a pungent, vinegar-like odor. Corrosive aqueous solution containing oxidizing agents. Water Reactivity: Miscible with water; dilution reduces reactivity but generates heat Extinguishing: Water spray, dry chemical, CO2; avoid organic materials and combustibles PPE: Level B minimum; SCBA required; chemical-resistant suit, gloves, and face shield for corrosive liquid protection Isolation: ERG 140: isolate spill 25-50m; evacuate 100m if large spill; 800m downwind for major fire — 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/3149 | 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)
UN3149 Hydrogen peroxide and peroxyacetic acid mixture, with acid(s), water and not more than 5% peroxyacetic acid, stabilized Cls5 ERG140 | allfirefighter.com/hazmat/un/3149SMS / 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/3149
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. 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; SCBA required; chemical-resistant suit, gloves, and face shield for corrosive liquid protection

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.