☣️ UN 1405 • CLASS 4
Calcium silicide
Placard: Dangerous When Wet. 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.
Advertisement
Quick details
UN 1405
Class: 4
Placard type: Dangerous When Wet
ERG: Guide 138 (check current ERG)
Isolation: ERG 138: isolate 25-50m in all directions; evacuate immediate area if water contact occurs or fire develops
Chemical & Response Details
| Also known as | Calcium disilicideSilicide of calciumCalcium silicon alloy |
| CAS Number | 12013-56-8 |
| Appearance | Gray to black crystalline solid or powder with no distinct odor. Hygroscopic material that reacts with moisture. |
| Flash Point | Not applicable (water-reactive solid) |
| Boiling Point | Not applicable (decomposes on contact with water) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts violently with water producing flammable hydrogen and silane gases; may spontaneously ignite |
| Extinguishing | Dry chemical, dry sand, soda ash; never use water or foam |
| PPE | ⚠️ Level B minimum; SCBA required; chemical-resistant suit for spill response |
| Isolation | ERG 138: isolate 25-50m in all directions; evacuate immediate area if water contact occurs or fire develops |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- 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
First actions (field-minded)
- 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).
Advertisement
📋 Copy & Share
UN 1405 — Calcium silicide HAZMAT RADIO NOTE — UN 1405
Product: Calcium silicide
Class 4 / Dangerous When Wet / ERG 138
PPE: Level B minimum; SCBA required; chemical-resistant suit for spill response
ISOLATION: ERG 138: isolate 25-50m in all directions; evacuate immediate area if water contact occurs or 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 1405 — Calcium silicide
Class: 4 | Placard: Dangerous When Wet | ERG Guide: 138
Appearance: Gray to black crystalline solid or powder with no distinct odor. Hygroscopic material that reacts with moisture.
Water Reactivity: Reacts violently with water producing flammable hydrogen and silane gases; may spontaneously ignite
Extinguishing: Dry chemical, dry sand, soda ash; never use water or foam
PPE: Level B minimum; SCBA required; chemical-resistant suit for spill response
Isolation: ERG 138: isolate 25-50m in all directions; evacuate immediate area if water contact occurs or 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 —
• 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/1405 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1405 Calcium silicide Cls4 ERG138 | ERG 138: isolate 25-50m in all directions; evacuate immediate area if water cont | allfirefighter.com/hazmat/un/1405SMS / 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/1405
Advertisement
FAQ
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 suit for spill response
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.