☣️ UN 2546 • CLASS 4

UN 2546 — Titanium powder, dry

Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

🚒☣️
⚠️ 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.

Dry titanium powder is a reactive metal powder shipped as UN 2546. Fine dry particles can ignite in air or moist conditions and can burn with intense heat.

Hazard overview: Titanium powder presents spontaneous combustion, dust ignition and re-ignition hazards. Water, foam or CO2 may be unsafe on burning powder unless the SDS and incident command confirm otherwise.

Response guidance: Isolate the area, avoid disturbing powder and keep ignition sources away. Use Class D dry powder, dry sand or other approved dry media. Monitor for re-ignition after control.

Firefighter training notes: Train firefighters on Class D metal fire tactics, dry media placement and avoiding dust disturbance. Include re-ignition watch procedures.

Regulatory context: UN 2546 is transported as Titanium powder, dry, Class 4 spontaneously combustible material. Confirm package condition and exact product form.

Storage & handling: Store dry in closed containers away from moisture, oxidizers, acids, heat and ignition sources. Prevent powder leaks and dust buildup.

Advertisement

UN 2546 Quick Details

UN 2546
Product name: Titanium powder, dry
DOT Class: 4
Placard type: Spontaneously Combustible
ERG Guide: 135 (check current ERG)
Initial isolation: ERG 135: isolate spill/leak 25m all directions; if fire, isolate 800m all directions, consider evacuation 800m

Common Hazards of UN 2546

  • Dry titanium powder is a spontaneously combustible metal powder; fine particles can ignite in air or moist air.
  • Burning powder can produce an intense, very hot metal fire.
  • Dust clouds may flash or explode if dispersed near an ignition source.
  • Water, foam or CO2 may react, spread burning powder or worsen the incident.
  • Moisture can promote heating and ignition in finely divided material.
  • Fire may produce irritating titanium oxide smoke.
  • Material may re-ignite after apparent extinguishment.

Chemical Identity & Physical Properties

Titanium powder is a gray to dark gray metallic powder. The finer and drier the powder, the greater the ignition and dust fire hazard.

Also known asTitanium metal powderTitanium dustTi powderTitanium particulate
CAS Number7440-32-6
AppearanceGray to dark gray metallic powder. Odorless. Exists as a fine to coarse dry powder at room temperature.
Flash PointNot applicable (pyrophoric metal powder)
Boiling Point3287C (5949F)
Vapor DensityNot applicable (solid metal powder)
Water ReactivityReacts with moisture in air; may ignite spontaneously when damp or in humid conditions
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 2546

Extinguishing Media

Use Class D dry powder, dry sand or SDS-approved dry media. Do NOT use water, foam or CO2 on burning titanium powder.

PPE Requirements

⚠️ Level B minimum with SCBA; full fire-resistant clothing for fire exposure; avoid dust inhalation

Use SCBA for smoke, dust or unknown atmosphere. Fire-resistant clothing and protective equipment suitable for reactive metal fires are required.

Isolation & Evacuation

ERG 135: isolate spill/leak 25m all directions; if fire, isolate 800m all directions, consider evacuation 800m
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 135).

First Actions for a UN 2546 Incident

  • Call 911 and the emergency response number on the shipping papers.
  • Keep unauthorized personnel away and avoid disturbing the powder.
  • Stay upwind, uphill and upstream of dust and smoke.
  • Avoid breathing dust or smoke; prevent skin and eye contact.
  • Do not touch damaged containers without PPE and reactive-metal response guidance.
  • Keep water and incompatible extinguishing agents away from burning powder.
  • Use ERG 135, SDS and shipping papers to confirm dry media, isolation and cleanup tactics.
Advertisement

📋 Copy & Share Field Card

UN 2546 — Titanium powder, dry
HAZMAT RADIO NOTE — UN 2546 Product: Titanium powder, dry Class 4 / Spontaneously Combustible / ERG 135 PPE: Level B minimum with SCBA; full fire-resistant clothing for fire exposure; avoid dust inhalation ISOLATION: ERG 135: isolate spill/leak 25m all directions; if fire, isolate 800m all directions, consider evacuation 800m 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 2546 — Titanium powder, dry Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 135 Appearance: Gray to dark gray metallic powder. Odorless. Exists as a fine to coarse dry powder at room temperature. Water Reactivity: Reacts with moisture in air; may ignite spontaneously when damp or in humid conditions Extinguishing: Use Class D dry powder, dry sand or SDS-approved dry media. Do NOT use water, foam or CO2 on burning titanium powder. PPE: Level B minimum with SCBA; full fire-resistant clothing for fire exposure; avoid dust inhalation Isolation: ERG 135: isolate spill/leak 25m all directions; if fire, isolate 800m all directions, consider evacuation 800m — Key Hazards — • Dry titanium powder is a spontaneously combustible metal powder; fine particles can ignite in air or moist air. • Burning powder can produce an intense, very hot metal fire. • Dust clouds may flash or explode if dispersed near an ignition source. — First Actions — • Call 911 and the emergency response number on the shipping papers. • Keep unauthorized personnel away and avoid disturbing the powder. • Stay upwind, uphill and upstream of dust and smoke. • Avoid breathing dust or smoke; prevent skin and eye contact. SOURCE: allfirefighter.com/hazmat/un/titanium-powder-dry-un-2546 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN2546 Titanium powder, dry Cls4 ERG135 | allfirefighter.com/hazmat/un/titanium-powder-dry-un-2546SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS.

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/titanium-powder-dry-un-2546

Related UN Numbers in Class 4

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
Advertisement

Frequently Asked Questions about UN 2546

Fine dry titanium powder can ignite in air or moisture and burn at very high temperature.

No. Water can be unsafe on reactive metal powder fires; use Class D dry media or SDS-approved agents.

A dispersed dust cloud can flash or explode if an ignition source is present.

Reactive metal powders can re-ignite from retained heat or exposed unburned material.

SCBA and fire-resistant protection suitable for reactive metal fires are needed.

ERG 135, the SDS and shipping papers should be used together.
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.