☣️ UN 1571 • CLASS 4
Barium azide, wetted with not less than 50% water
Placard: Flammable Solid. 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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Quick details
UN 1571
Class: 4
Placard type: Flammable Solid
ERG: Guide 113 (check current ERG)
Isolation: ERG 113: isolate 100m all directions initially; if dry or suspected dry, treat as Class 1 explosive and evacuate 800m radius; keep material wet at all times
Chemical & Response Details
| Also known as | Barium diazideBarium azide hydrateAzide of bariumBarium azoimide |
| CAS Number | 18810-58-7 |
| Appearance | White to grayish crystalline solid when dry, appears as wetted paste or slurry with water. Odorless. Highly sensitive to shock, friction, and heat when dry. |
| Flash Point | Not applicable (wetted explosive solid) |
| Boiling Point | Not applicable (decomposes explosively when heated) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Stable when wet; water is used as desensitizing agent. Do not allow to dry out. |
| Extinguishing | Keep wetted with water; do not use foam or dry chemical on dry material; water spray to maintain wetness |
| PPE | ⚠️ Level A required for dry or drying material; Level B minimum for wetted material; SCBA mandatory; avoid all ignition sources |
| Isolation | ERG 113: isolate 100m all directions initially; if dry or suspected dry, treat as Class 1 explosive and evacuate 800m radius; keep material wet at all times |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Flammable/combustible material.
- May be ignited by heat, sparks or flames.
- DRIED OUT material may explode if exposed to heat, flame, friction or shock; treat as an
- Keep material wet with water or treat as an explosive (GUIDE 112).
- Runoff to sewer may create fire or explosion hazard.
- Some are toxic and may be fatal if inhaled, ingested or absorbed through skin. Specifically,
- Contact may cause burns to skin and eyes.
- Fire may produce irritating, corrosive and/or toxic gases.
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 immediately for at least 100 meters (330 feet) in all directions.
- Consider initial evacuation for 500 meters (1/3 mile) in all directions.
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UN 1571 — Barium azide, wetted with not less than HAZMAT RADIO NOTE — UN 1571
Product: Barium azide, wetted with not less than 50% water
Class 4 / Flammable Solid / ERG 113
PPE: Level A required for dry or drying material; Level B minimum for wetted material; SCBA mandatory; avoid all ignition sources
ISOLATION: ERG 113: isolate 100m all directions initially; if dry or suspected dry, treat as Class 1 explosive and evacuate 800m radius; keep material wet at all times
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 1571 — Barium azide, wetted with not less than 50% water
Class: 4 | Placard: Flammable Solid | ERG Guide: 113
Appearance: White to grayish crystalline solid when dry, appears as wetted paste or slurry with water. Odorless. Highly sensitive to shock, friction, and heat when dry.
Water Reactivity: Stable when wet; water is used as desensitizing agent. Do not allow to dry out.
Extinguishing: Keep wetted with water; do not use foam or dry chemical on dry material; water spray to maintain wetness
PPE: Level A required for dry or drying material; Level B minimum for wetted material; SCBA mandatory; avoid all ignition sources
Isolation: ERG 113: isolate 100m all directions initially; if dry or suspected dry, treat as Class 1 explosive and evacuate 800m radius; keep material wet at all times
— Key Hazards —
• Flammable/combustible material.
• May be ignited by heat, sparks or flames.
• DRIED OUT material may explode if exposed to heat, flame, friction or shock; treat as an
— 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/1571 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1571 Barium azide, wetted with not less than 50% water Cls4 ERG113 | allfirefighter.com/hazmat/un/1571SMS / 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/1571
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FAQ
Flammable/combustible material. May be ignited by heat, sparks or flames. DRIED OUT material may explode if exposed to heat, flame, friction or shock; treat as an Keep material wet with water or treat as an explosive (GUIDE 112). Runoff to sewer may create fire or explosion hazard. Some are toxic and may be fatal if inhaled, ingested or absorbed through skin. Specifically, Contact may cause burns to skin and eyes. Fire may produce irritating, corrosive and/or toxic gases.
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 A required for dry or drying material; Level B minimum for wetted material; SCBA mandatory; avoid all ignition sources
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 113 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.