☣️ UN 1855 • CLASS 4
UN 1855 — Calcium alloys, pyrophoric
Placard: Spontaneously Combustible. ERG Guide 135. 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 1855 Quick Details
UN 1855
Product name: Calcium alloys, pyrophoric
DOT Class: 4
Placard type: Spontaneously Combustible
ERG Guide: 135 (check current ERG)
Initial isolation: ERG 135: isolate 25-50m all directions initially; for large spills isolate 100m; evacuate 800m downwind if fire threatens containers
Common Hazards of UN 1855
- Flammable/combustible material.
- May ignite on contact with moist air or moisture.
- May burn rapidly with flare-burning effect.
- Some react vigorously or explosively on contact with water.
- Some may decompose explosively when heated or involved in a fire.
- May re-ignite after fire is extinguished.
- Runoff may create fire or explosion hazard.
- Containers may explode when heated.
Chemical Identity & Physical Properties
| Also known as | Pyrophoric calcium alloysCalcium metal alloysCalcium-magnesium alloysCalcium-aluminum alloys |
| Appearance | Silvery-gray to dark gray metallic solid alloy, often in powder or granular form. Odorless. Pyrophoric nature means spontaneous ignition possible upon exposure to air or moisture. |
| Flash Point | Not applicable (pyrophoric solid - ignites spontaneously) |
| Boiling Point | Not applicable (varies by alloy composition, typically >1400C) |
| 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 1855
Extinguishing Media
Dry sand, dry dolomite, dry graphite powder, soda ash; NO water, foam, halogenated agents, or CO2
PPE Requirements
⚠️ Level B minimum with full face SCBA; fire-resistant clothing; do not handle in humid conditions; avoid all moisture contact
Isolation & Evacuation
ERG 135: isolate 25-50m all directions initially; for large spills isolate 100m; evacuate 800m downwind if fire threatens containers
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 135).
First Actions for a UN 1855 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Stay upwind, uphill and/or upstream.
- Keep unauthorized personnel away.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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📋 Copy & Share Field Card
UN 1855 — Calcium alloys, pyrophoricHAZMAT RADIO NOTE — UN 1855
Product: Calcium alloys, pyrophoric
Class 4 / Spontaneously Combustible / ERG 135
PPE: Level B minimum with full face SCBA; fire-resistant clothing; do not handle in humid conditions; avoid all moisture contact
ISOLATION: ERG 135: isolate 25-50m all directions initially; for large spills isolate 100m; evacuate 800m downwind if fire threatens containers
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 1855 — Calcium alloys, pyrophoric
Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 135
Appearance: Silvery-gray to dark gray metallic solid alloy, often in powder or granular form. Odorless. Pyrophoric nature means spontaneous ignition possible upon exposure to air or moisture.
Water Reactivity: Reacts violently with water producing flammable hydrogen gas and heat; may ignite spontaneously
Extinguishing: Dry sand, dry dolomite, dry graphite powder, soda ash; NO water, foam, halogenated agents, or CO2
PPE: Level B minimum with full face SCBA; fire-resistant clothing; do not handle in humid conditions; avoid all moisture contact
Isolation: ERG 135: isolate 25-50m all directions initially; for large spills isolate 100m; evacuate 800m downwind if fire threatens containers
— Key Hazards —
• Flammable/combustible material.
• May ignite on contact with moist air or moisture.
• May burn rapidly with flare-burning effect.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Stay upwind, uphill and/or upstream.
• Keep unauthorized personnel away.
• 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/1855 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1855 Calcium alloys, pyrophoric Cls4 ERG135 | allfirefighter.com/hazmat/un/1855SMS / 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/1855
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Frequently Asked Questions about UN 1855
Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Stay upwind, uphill and/or upstream. Keep unauthorized personnel away.
Level B minimum with full face SCBA; fire-resistant clothing; do not handle in humid conditions; avoid all moisture contact
Water reactivity: Reacts violently with water producing flammable hydrogen gas and heat; may ignite spontaneously. Recommended extinguishing: Dry sand, dry dolomite, dry graphite powder, soda ash; NO water, foam, halogenated agents, or CO2.
ERG Guide 135 recommendation: ERG 135: isolate 25-50m all directions initially; for large spills isolate 100m; evacuate 800m downwind if fire threatens containers
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 135 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.