☣️ UN 2033 • CLASS 8

Potassium monoxide

Placard: Corrosive. 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 2033
Class: 8
Placard type: Corrosive
ERG: Guide 154 (check current ERG)
Isolation: ERG 154: isolate spill 25m in all directions; if large spill isolate 50m and consider evacuation 300m downwind
Chemical & Response Details
Also known asPotassium oxideDipotassium oxideKaliumoxidPotassium oxide (K2O)
CAS Number12136-45-7
AppearanceGray to white crystalline solid or powder. Odorless. Hygroscopic and reacts vigorously with moisture.
Flash PointNot applicable (inorganic oxide)
Boiling PointDecomposes before boiling
Vapor DensityNot applicable (solid)
Water ReactivityReacts violently with water, generating heat and forming corrosive potassium hydroxide solution
ExtinguishingDry chemical, dry sand, soda ash; do not use water or foam
PPE⚠️ Level B minimum; SCBA required; chemical-resistant suit, gloves, and boots; face shield
IsolationERG 154: isolate spill 25m in all directions; if large spill isolate 50m and consider evacuation 300m downwind
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury
  • Contact with molten substance may cause severe burns to skin and eyes.
  • Avoid any skin contact.
  • Fire may produce irritating, corrosive and/or toxic gases.
  • Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
  • Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive
  • Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.).
  • Corrosives in contact with metals may evolve flammable hydrogen gas.
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
  • For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
  • For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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UN 2033 — Potassium monoxide
HAZMAT RADIO NOTE — UN 2033 Product: Potassium monoxide Class 8 / Corrosive / ERG 154 PPE: Level B minimum; SCBA required; chemical-resistant suit, gloves, and boots; face shield ISOLATION: ERG 154: isolate spill 25m in all directions; if large spill isolate 50m and consider evacuation 300m 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 2033 — Potassium monoxide Class: 8 | Placard: Corrosive | ERG Guide: 154 Appearance: Gray to white crystalline solid or powder. Odorless. Hygroscopic and reacts vigorously with moisture. Water Reactivity: Reacts violently with water, generating heat and forming corrosive potassium hydroxide solution Extinguishing: Dry chemical, dry sand, soda ash; do not use water or foam PPE: Level B minimum; SCBA required; chemical-resistant suit, gloves, and boots; face shield Isolation: ERG 154: isolate spill 25m in all directions; if large spill isolate 50m and consider evacuation 300m downwind — Key Hazards — • TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury • Contact with molten substance may cause severe burns to skin and eyes. • Avoid any skin contact. — 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/2033 | 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)
UN2033 Potassium monoxide Cls8 ERG154 | ERG 154: isolate spill 25m in all directions; if large spill isolate 50m and con | allfirefighter.com/hazmat/un/2033SMS / 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/2033
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

TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas.

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 boots; face shield

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 154 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.