☣️ UN 1423 • CLASS 4
UN 1423 — Rubidium
Placard: Dangerous When Wet. ERG Guide 138. 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.
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UN 1423 Quick Details
UN 1423
Product name: Rubidium
DOT Class: 4
Placard type: Dangerous When Wet
ERG Guide: 138 (check current ERG)
Initial isolation: ERG 138: isolate 25-50m in all directions. If tank/rail car involved in fire, isolate 800m and consider evacuation.
Common Hazards of UN 1423
- 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 as | RbRubidium metalRubidium element |
| CAS Number | 7440-17-7 |
| Appearance | Soft, silvery-white metallic solid at room temperature. Highly reactive alkali metal with a slight golden tint. No distinct odor. |
| Flash Point | Not applicable (ignites spontaneously on contact with water or moist air) |
| Boiling Point | 688C (1270F) |
| Vapor Density | Not applicable (solid metal at room temperature) |
| Water Reactivity | Reacts violently and explosively with water, producing flammable hydrogen gas and heat. May ignite spontaneously. Never use water. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1423
Extinguishing Media
Dry sand, soda ash, dry chemical (Class D for metal fires). NO water, foam, or CO2.
PPE Requirements
⚠️ Level B minimum with full face SCBA. Chemical-resistant gloves and suit. Handle only in inert atmosphere (argon/nitrogen). Keep moisture away.
Isolation & Evacuation
ERG 138: isolate 25-50m in all directions. If tank/rail car involved in fire, isolate 800m and consider evacuation.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 138).
First Actions for a UN 1423 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 1423 — RubidiumHAZMAT RADIO NOTE — UN 1423
Product: Rubidium
Class 4 / Dangerous When Wet / ERG 138
PPE: Level B minimum with full face SCBA. Chemical-resistant gloves and suit. Handle only in inert atmosphere (argon/nitrogen). Keep moisture away.
ISOLATION: ERG 138: isolate 25-50m in all directions. If tank/rail car involved in fire, isolate 800m 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.
=== IC HAZMAT BRIEFING ===
UN 1423 — Rubidium
Class: 4 | Placard: Dangerous When Wet | ERG Guide: 138
Appearance: Soft, silvery-white metallic solid at room temperature. Highly reactive alkali metal with a slight golden tint. No distinct odor.
Water Reactivity: Reacts violently and explosively with water, producing flammable hydrogen gas and heat. May ignite spontaneously. Never use water.
Extinguishing: Dry sand, soda ash, dry chemical (Class D for metal fires). NO water, foam, or CO2.
PPE: Level B minimum with full face SCBA. Chemical-resistant gloves and suit. Handle only in inert atmosphere (argon/nitrogen). Keep moisture away.
Isolation: ERG 138: isolate 25-50m in all directions. If tank/rail car involved in fire, isolate 800m 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/1423 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1423 Rubidium Cls4 ERG138 | ERG 138: isolate 25-50m in all directions. If tank/rail car involved in fire, is | allfirefighter.com/hazmat/un/1423SMS / 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/1423
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Frequently Asked Questions about UN 1423
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 with full face SCBA. Chemical-resistant gloves and suit. Handle only in inert atmosphere (argon/nitrogen). Keep moisture away.
Water reactivity: Reacts violently and explosively with water, producing flammable hydrogen gas and heat. May ignite spontaneously. Never use water.. Recommended extinguishing: Dry sand, soda ash, dry chemical (Class D for metal fires). NO water, foam, or CO2..
ERG Guide 138 recommendation: ERG 138: isolate 25-50m in all directions. If tank/rail car involved in fire, isolate 800m 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.