☣️ UN 1437 • CLASS 4

UN 1437 — Zirconium hydride

Placard: Flammable Solid. ERG Guide 138. 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 1437 Quick Details

UN 1437
Product name: Zirconium hydride
DOT Class: 4
Placard type: Flammable Solid
ERG Guide: 138 (check current ERG)
Initial isolation: ERG 138: isolate 100m all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation

Common Hazards of UN 1437

  • Produce flammable gases on contact with water.
  • May ignite on contact with water or moist air.
  • Some react vigorously or explosively on contact with water.
  • May be ignited by heat, sparks or flames.
  • May re-ignite after fire is extinguished.
  • Some are transported in highly flammable liquids.
  • Runoff may create fire or explosion hazard.
  • Inhalation or contact with vapors, substance or decomposition products may cause severe injury or

Chemical Identity & Physical Properties

Also known asZirconium dihydrideZirconium hydride powderZirconium(II) hydrideZrH2
CAS Number7704-99-6
AppearanceGray to black metallic powder or crystalline solid, odorless. Stable in dry air but reacts with moisture.
Flash PointNot applicable (pyrophoric solid)
Boiling PointNot applicable (decomposes before boiling)
Vapor DensityNot applicable (solid)
Water ReactivityReacts with water producing flammable hydrogen gas and heat; may ignite spontaneously in moist air
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 1437

Extinguishing Media

Dry chemical, sand, dry graphite powder; DO NOT use water, foam, or CO2

PPE Requirements

⚠️ Level B minimum; SCBA required; chemical-resistant gloves and clothing; avoid moisture exposure

Isolation & Evacuation

ERG 138: isolate 100m all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 138).

First Actions for a UN 1437 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.
  • 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 300 meters (1000 feet).
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📋 Copy & Share Field Card

UN 1437 — Zirconium hydride
HAZMAT RADIO NOTE — UN 1437 Product: Zirconium hydride Class 4 / Flammable Solid / ERG 138 PPE: Level B minimum; SCBA required; chemical-resistant gloves and clothing; avoid moisture exposure ISOLATION: ERG 138: isolate 100m all directions; if tank/rail car involved in fire, isolate 800m in all directions 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 1437 — Zirconium hydride Class: 4 | Placard: Flammable Solid | ERG Guide: 138 Appearance: Gray to black metallic powder or crystalline solid, odorless. Stable in dry air but reacts with moisture. Water Reactivity: Reacts with water producing flammable hydrogen gas and heat; may ignite spontaneously in moist air Extinguishing: Dry chemical, sand, dry graphite powder; DO NOT use water, foam, or CO2 PPE: Level B minimum; SCBA required; chemical-resistant gloves and clothing; avoid moisture exposure Isolation: ERG 138: isolate 100m all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation — Key Hazards — • Produce flammable gases on contact with water. • May ignite on contact with water or moist air. • Some react vigorously or explosively on contact with water. — 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/1437 | 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)
UN1437 Zirconium hydride Cls4 ERG138 | ERG 138: isolate 100m all directions; if tank/rail car involved in fire, isolate | allfirefighter.com/hazmat/un/1437SMS / 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/1437

Related UN Numbers in Class 4

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 1437

Produce flammable gases on contact with water. May ignite on contact with water or moist air. Some react vigorously or explosively on contact with water. May be ignited by heat, sparks or flames. May re-ignite after fire is extinguished. Some are transported in highly flammable liquids. Runoff may create fire or explosion hazard. Inhalation or contact with vapors, substance or decomposition products may cause severe injury 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 gloves and clothing; avoid moisture exposure

Water reactivity: Reacts with water producing flammable hydrogen gas and heat; may ignite spontaneously in moist air. Recommended extinguishing: Dry chemical, sand, dry graphite powder; DO NOT use water, foam, or CO2.

ERG Guide 138 recommendation: ERG 138: isolate 100m all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 138 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.