☣️ UN 2548 • CLASS 2

UN 2548 — Chlorine pentafluoride

Placard: Toxic Gas. ERG Guide 124. 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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UN 2548 Quick Details

UN 2548
Product name: Chlorine pentafluoride
DOT Class: 2
Placard type: Toxic Gas
ERG Guide: 124 (check current ERG)
Initial isolation: ERG 124: Initial isolation 100m all directions. Protective action distance: 0.5km daytime, 1.0km nighttime for small spills; 1.4km daytime, 4.2km nighttime for large spills.

Common Hazards of UN 2548

  • TOXIC and/or CORROSIVE; may be fatal if inhaled or absorbed through skin.
  • Fire will produce irritating, corrosive and/or toxic gases.
  • Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
  • Runoff from fire control or dilution water may cause environmental contamination.
  • Substance does not burn but will support combustion.
  • Vapors from liquefied gas are initially heavier than air and spread along ground.
  • These are strong oxidizers and will react vigorously or explosively with many materials including fuels.
  • May ignite combustibles (wood, paper, oil, clothing, etc.).

Chemical Identity & Physical Properties

Also known asChlorine(V) fluoridePentafluorochlorineClF5
CAS Number13637-63-3
AppearanceColorless to pale yellow gas with a sweet, suffocating odor. Highly reactive and corrosive. Liquefies at -13°C (8.6°F).
Flash PointNot applicable (non-flammable oxidizing gas)
Boiling Point-13°C (8.6°F)
Vapor Density4.4 (much heavier than air)
Water ReactivityReacts violently with water producing heat, toxic hydrofluoric acid and chlorine fumes. Do not use water directly on material.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 2548

Extinguishing Media

Do not use water or foam. Use dry chemical or sand for small fires. Evacuate and let large fires burn.

PPE Requirements

⚠️ Level A fully encapsulated suit required. SCBA mandatory. Chemical-resistant gloves and boots. Gas causes severe burns on contact.

Isolation & Evacuation

ERG 124: Initial isolation 100m all directions. Protective action distance: 0.5km daytime, 1.0km nighttime for small spills; 1.4km daytime, 4.2km nighttime for large spills.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 124).

First Actions for a UN 2548 Incident

  • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
  • Keep unauthorized personnel away.
  • Stay upwind, uphill and/or upstream.
  • Many gases are heavier than air and will spread along the ground and collect in low or confined areas
  • Ventilate closed spaces before entering, but only if properly trained and equipped.
  • Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
  • See Table 1 - Initial Isolation and Protective Action Distances.
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📋 Copy & Share Field Card

UN 2548 — Chlorine pentafluoride
HAZMAT RADIO NOTE — UN 2548 Product: Chlorine pentafluoride Class 2 / Toxic Gas / ERG 124 PPE: Level A fully encapsulated suit required. SCBA mandatory. Chemical-resistant gloves and boots. Gas causes severe burns on contact. ISOLATION: ERG 124: Initial isolation 100m all directions. Protective action distance: 0.5km daytime, 1.0km nighttime for small spills; 1.4km daytime, 4.2km nighttime for large spills. 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 2548 — Chlorine pentafluoride Class: 2 | Placard: Toxic Gas | ERG Guide: 124 Appearance: Colorless to pale yellow gas with a sweet, suffocating odor. Highly reactive and corrosive. Liquefies at -13°C (8.6°F). Water Reactivity: Reacts violently with water producing heat, toxic hydrofluoric acid and chlorine fumes. Do not use water directly on material. Extinguishing: Do not use water or foam. Use dry chemical or sand for small fires. Evacuate and let large fires burn. PPE: Level A fully encapsulated suit required. SCBA mandatory. Chemical-resistant gloves and boots. Gas causes severe burns on contact. Isolation: ERG 124: Initial isolation 100m all directions. Protective action distance: 0.5km daytime, 1.0km nighttime for small spills; 1.4km daytime, 4.2km nighttime for large spills. — Key Hazards — • TOXIC and/or CORROSIVE; may be fatal if inhaled or absorbed through skin. • Fire will produce irritating, corrosive and/or toxic gases. • Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. — 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. • Many gases are heavier than air and will spread along the ground and collect in low or confined areas SOURCE: allfirefighter.com/hazmat/un/2548 | 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)
UN2548 Chlorine pentafluoride Cls2 ERG124 | ERG 124: Initial isolation 100m all directions. Protective action distance: 0.5k | allfirefighter.com/hazmat/un/2548SMS / 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/2548

Related UN Numbers in Class 2

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 2548

TOXIC and/or CORROSIVE; may be fatal if inhaled or absorbed through skin. Fire will produce irritating, corrosive and/or toxic gases. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Runoff from fire control or dilution water may cause environmental contamination. Substance does not burn but will support combustion. Vapors from liquefied gas are initially heavier than air and spread along ground. These are strong oxidizers and will react vigorously or explosively with many materials including fuels. May ignite combustibles (wood, paper, oil, clothing, etc.).

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 A fully encapsulated suit required. SCBA mandatory. Chemical-resistant gloves and boots. Gas causes severe burns on contact.

Water reactivity: Reacts violently with water producing heat, toxic hydrofluoric acid and chlorine fumes. Do not use water directly on material.. Recommended extinguishing: Do not use water or foam. Use dry chemical or sand for small fires. Evacuate and let large fires burn..

ERG Guide 124 recommendation: ERG 124: Initial isolation 100m all directions. Protective action distance: 0.5km daytime, 1.0km nighttime for small spills; 1.4km daytime, 4.2km nighttime for large spills.

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 124 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.