☣️ UN 1404 • CLASS 4
UN 1404 — Calcium hydride
Placard: Dangerous When Wet. 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.
Calcium hydride is a highly reactive substance that can produce flammable gases when exposed to water. It is essential to handle this substance with extreme caution.
Hazard overview: Calcium hydride can react violently with water, producing flammable hydrogen gas and heat. It may also ignite spontaneously.
Response guidance: In case of a spill, isolate the area 100m in all directions and protect from moisture and water sources. Evacuate the area if a fire develops. Use dry sand, dry chemical, or soda ash to extinguish the fire.
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UN 1404 Quick Details
UN 1404
Product name: Calcium hydride
DOT Class: 4
Placard type: Dangerous When Wet
ERG Guide: 138 (check current ERG)
Initial isolation: ERG 138: Initial isolation 100m all directions. Protect from moisture and water sources. Evacuate area if fire develops.
Common Hazards of UN 1404
- 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
Calcium hydride appears as a gray to white crystalline powder or lumps, odorless when dry.
| Also known as | Calcium dihydrideHydrolithCaH2 |
| CAS Number | 7789-78-8 |
| Appearance | Gray to white crystalline powder or lumps, odorless when dry. Solid at room temperature. |
| Flash Point | Not applicable (water-reactive solid) |
| Boiling Point | Not applicable (decomposes above 600C) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts violently with water, producing flammable hydrogen gas and heat. May ignite spontaneously. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1404
Extinguishing Media
Dry sand, dry chemical, soda ash. DO NOT use water, foam, or CO2.
PPE Requirements
⚠️ Level B minimum with SCBA required. Full protective clothing to prevent skin contact with material or moisture.
Level B minimum personal protective equipment (PPE) is required, including a self-contained breathing apparatus (SCBA) and full protective clothing to prevent skin contact with material or moisture.
Isolation & Evacuation
ERG 138: Initial isolation 100m all directions. Protect from moisture and water sources. Evacuate area if fire develops.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 138).
First Actions for a UN 1404 Incident
- 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 1404 — Calcium hydrideHAZMAT RADIO NOTE — UN 1404
Product: Calcium hydride
Class 4 / Dangerous When Wet / ERG 138
PPE: Level B minimum with SCBA required. Full protective clothing to prevent skin contact with material or moisture.
ISOLATION: ERG 138: Initial isolation 100m all directions. Protect from moisture and water sources. Evacuate area if fire develops.
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 1404 — Calcium hydride
Class: 4 | Placard: Dangerous When Wet | ERG Guide: 138
Appearance: Gray to white crystalline powder or lumps, odorless when dry. Solid at room temperature.
Water Reactivity: Reacts violently with water, producing flammable hydrogen gas and heat. May ignite spontaneously.
Extinguishing: Dry sand, dry chemical, soda ash. DO NOT use water, foam, or CO2.
PPE: Level B minimum with SCBA required. Full protective clothing to prevent skin contact with material or moisture.
Isolation: ERG 138: Initial isolation 100m all directions. Protect from moisture and water sources. Evacuate area if fire develops.
— 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 —
• 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
SOURCE: allfirefighter.com/hazmat/un/1404 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN1404 Calcium hydride Cls4 ERG138 | ERG 138: Initial isolation 100m all directions. Protect from moisture and water | allfirefighter.com/hazmat/un/1404SMS / 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/calcium-hydride-un-1404
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Frequently Asked Questions about UN 1404
Yes, UN 1404 can produce flammable gases on contact with water.
Yes, UN 1404 may ignite spontaneously on contact with water.
Avoid skin contact with material or moisture when handling UN 1404.
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.