☣️ UN 1557 • CLASS 6
Arsenic compound, solid, n.o.s.
Placard: Toxic. 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 1557
Class: 6
Placard type: Toxic
ERG: Guide 152 (check current ERG)
Isolation: ERG 152: Initial isolation 25 meters in all directions; for large spills isolate 50 meters; protect personnel and prevent entry to contaminated area
Chemical & Response Details
| Also known as | Arsenic compoundsArsenical compoundsArsenic-containing solidsArsenic derivatives |
| Appearance | Variable appearance depending on specific compound; may be white, gray, yellow, or colorless crystalline solids or powders. Generally odorless or may have slight garlic-like odor. |
| Flash Point | Not applicable (non-flammable inorganic solid) |
| Boiling Point | Not applicable (varies by compound, many decompose before boiling) |
| Vapor Density | Not applicable (solid material) |
| Water Reactivity | Generally no significant reaction with water, though some compounds may dissolve slowly |
| Extinguishing | Not applicable for fire suppression; use dry sand, dry chemical, or earth to contain spills |
| PPE | ⚠️ Level B minimum required; SCBA and full chemical-resistant suit mandatory; avoid any skin contact due to extreme toxicity and absorption hazard |
| Isolation | ERG 152: Initial isolation 25 meters in all directions; for large spills isolate 50 meters; protect personnel and prevent entry to contaminated area |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Highly toxic, may be fatal if inhaled, ingested or absorbed through skin.
- Contact with molten substance may cause severe burns to skin and eyes.
- Avoid any skin contact.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
- Combustible material: may burn but does not ignite readily.
- Containers may explode when heated.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
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.
- 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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UN 1557 — Arsenic compound, solid, n.o.s. HAZMAT RADIO NOTE — UN 1557
Product: Arsenic compound, solid, n.o.s.
Class 6 / Toxic / ERG 152
PPE: Level B minimum required; SCBA and full chemical-resistant suit mandatory; avoid any skin contact due to extreme toxicity and absorption hazard
ISOLATION: ERG 152: Initial isolation 25 meters in all directions; for large spills isolate 50 meters; protect personnel and prevent entry to contaminated area
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 1557 — Arsenic compound, solid, n.o.s.
Class: 6 | Placard: Toxic | ERG Guide: 152
Appearance: Variable appearance depending on specific compound; may be white, gray, yellow, or colorless crystalline solids or powders. Generally odorless or may have slight garlic-like odor.
Water Reactivity: Generally no significant reaction with water, though some compounds may dissolve slowly
Extinguishing: Not applicable for fire suppression; use dry sand, dry chemical, or earth to contain spills
PPE: Level B minimum required; SCBA and full chemical-resistant suit mandatory; avoid any skin contact due to extreme toxicity and absorption hazard
Isolation: ERG 152: Initial isolation 25 meters in all directions; for large spills isolate 50 meters; protect personnel and prevent entry to contaminated area
— Key Hazards —
• Highly toxic, may be fatal if inhaled, ingested or absorbed through skin.
• Contact with molten substance may cause severe burns to skin and eyes.
• Avoid any skin contact.
— 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.
• 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/1557 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1557 Arsenic compound, solid, n.o.s. Cls6 ERG152 | allfirefighter.com/hazmat/un/1557SMS / 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/1557
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FAQ
Highly toxic, may be fatal if inhaled, ingested or absorbed through skin. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental Combustible material: may burn but does not ignite readily. Containers may explode when heated. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
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 required; SCBA and full chemical-resistant suit mandatory; avoid any skin contact due to extreme toxicity and absorption hazard
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 152 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.