☣️ UN 3482 • CLASS 4
UN 3482 — Alkaline earth metal dispersion, flammable
Placard: Dangerous When Wet. ERG Guide 138. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ Verification required:
Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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.
UN 3482 covers flammable alkaline earth metal dispersions, often suspended in an organic carrier liquid.
Hazard overview: Water or moist air may cause violent hydrogen release, heat, ignition, or fire spread. Some carrier liquids may also be flammable.
Response guidance: Keep the material dry, isolate the spill, prevent water runoff, and use dry sand, dry graphite, dry dolomite, or suitable Class D extinguishing agents.
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UN 3482 Quick Details
UN 3482
Product name: Alkaline earth metal dispersion, flammable
DOT Class: 4
Placard type: Dangerous When Wet
ERG Guide: 138 (check current ERG)
Initial isolation: ERG 138: Small spill isolate 50m all directions. Large spill isolate 150m all directions, consider evacuation 800m downwind if fire involves tank/rail car.
Common Hazards of UN 3482
- 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.
Chemical Identity & Physical Properties
Alkaline earth metal dispersion or suspension in liquid medium typically has a gray to silvery appearance and may be in a hydrocarbon or other organic carrier liquid.
| Also known as | Alkaline earth metal dispersionGroup 2 metal dispersionBeryllium/Magnesium/Calcium/Strontium/Barium dispersion |
| Appearance | Metallic dispersion or suspension in liquid medium, typically gray to silvery appearance. May be in hydrocarbon or other organic carrier liquid. Alkaline earth metals include beryllium, magnesium, calcium, strontium, and barium. |
| Flash Point | Not applicable (dispersed metal, reactivity hazard primary concern) |
| Boiling Point | Not applicable (mixture, dependent on carrier liquid) |
| Vapor Density | Variable depending on carrier liquid composition |
| Water Reactivity | Reacts vigorously to violently with water producing flammable hydrogen gas and heat. May ignite spontaneously on contact with moisture. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3482
Extinguishing Media
Dry chemical, dry sand, dry dolomite, dry graphite. DO NOT use water, foam, CO2, or halogenated agents.
PPE Requirements
⚠️ Level B minimum with SCBA required. Full protective clothing and face shield. Avoid any moisture contact.
Level B with SCBA, face shield, and full protective clothing is recommended. Avoid all moisture contact and approach from upwind.
Isolation & Evacuation
ERG 138: Small spill isolate 50m all directions. Large spill isolate 150m all directions, consider evacuation 800m downwind if fire involves tank/rail car.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 138).
First Actions for a UN 3482 Incident
- CALL 911. Then call the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate the spill or leak area in all directions using ERG guidance for the material and package size.
- Consider initial downwind evacuation for at least 300 meters (1000 feet).
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📋 Copy & Share Field Card
UN 3482 — Alkaline earth metal dispersion, flammabHAZMAT RADIO NOTE — UN 3482
Product: Alkaline earth metal dispersion, flammable
Class 4 / Dangerous When Wet / ERG 138
PPE: Level B minimum with SCBA required. Full protective clothing and face shield. Avoid any moisture contact.
ISOLATION: ERG 138: Small spill isolate 50m all directions. Large spill isolate 150m all directions, consider evacuation 800m downwind if fire involves tank/rail car.
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 3482 — Alkaline earth metal dispersion, flammable
Class: 4 | Placard: Dangerous When Wet | ERG Guide: 138
Appearance: Metallic dispersion or suspension in liquid medium, typically gray to silvery appearance. May be in hydrocarbon or other organic carrier liquid. Alkaline earth metals include beryllium, magnesium, calcium, strontium, and barium.
Water Reactivity: Reacts vigorously to violently with water producing flammable hydrogen gas and heat. May ignite spontaneously on contact with moisture.
Extinguishing: Dry chemical, dry sand, dry dolomite, dry graphite. DO NOT use water, foam, CO2, or halogenated agents.
PPE: Level B minimum with SCBA required. Full protective clothing and face shield. Avoid any moisture contact.
Isolation: ERG 138: Small spill isolate 50m all directions. Large spill isolate 150m all directions, consider evacuation 800m downwind if fire involves tank/rail car.
— 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 the emergency response number on the shipping paper, if available.
• 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/alkaline-earth-metal-dispersion-un-3482 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3482 Alkaline earth metal dispersion, flammable Cls4 ERG138 | allfirefighter.com/hazmat/un/alkaline-earth-metal-dispersion-un-3482SMS / 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/alkaline-earth-metal-dispersion-un-3482
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Frequently Asked Questions about UN 3482
Yes. The dispersion can ignite and may release flammable hydrogen gas on water contact.
Yes. It can react vigorously or violently with water, releasing hydrogen and heat.
Level B with SCBA, face shield, and full protective clothing is recommended.
Keep dry, isolate the area, and use only dry extinguishing media such as dry sand, graphite, or Class D agents.
UN 3482 is assigned to ERG Guide 138 for initial emergency response guidance.
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.