☣️ UN 1678 • CLASS 6
Potassium arsenite
Placard: Toxic. 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 1678
Class: 6
Placard type: Toxic
ERG: Guide 154 (check current ERG)
Isolation: ERG 154: Initial isolation 25m all directions; Protective Action Distance 150m daytime, 300m nighttime for small spills; increase for large spills or fire involvement
Chemical & Response Details
| Also known as | Potassium metaarseniteArsenous acid potassium saltFowler's solution (historical)Potassium arsenite solution |
| CAS Number | 13464-35-2 |
| Appearance | White to grayish-white crystalline powder or hygroscopic solid. Typically odorless. May be encountered as an aqueous solution. |
| Flash Point | Not applicable (inorganic salt) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water forming toxic arsenite solutions; no violent reaction |
| Extinguishing | Water spray, fog, or foam acceptable for fire control; focus on containment and avoiding runoff |
| PPE | ⚠️ Level B minimum with SCBA required; impervious gloves and chemical-resistant suit; avoid all skin contact |
| Isolation | ERG 154: Initial isolation 25m all directions; Protective Action Distance 150m daytime, 300m nighttime for small spills; increase for large spills or fire involvement |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury
- 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
- Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive
- Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.).
- Corrosives in contact with metals may evolve flammable hydrogen gas.
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
- 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
Advertisement
📋 Copy & Share
UN 1678 — Potassium arsenite HAZMAT RADIO NOTE — UN 1678
Product: Potassium arsenite
Class 6 / Toxic / ERG 154
PPE: Level B minimum with SCBA required; impervious gloves and chemical-resistant suit; avoid all skin contact
ISOLATION: ERG 154: Initial isolation 25m all directions; Protective Action Distance 150m daytime, 300m nighttime for small spills; increase for large spills or fire involvement
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 1678 — Potassium arsenite
Class: 6 | Placard: Toxic | ERG Guide: 154
Appearance: White to grayish-white crystalline powder or hygroscopic solid. Typically odorless. May be encountered as an aqueous solution.
Water Reactivity: Soluble in water forming toxic arsenite solutions; no violent reaction
Extinguishing: Water spray, fog, or foam acceptable for fire control; focus on containment and avoiding runoff
PPE: Level B minimum with SCBA required; impervious gloves and chemical-resistant suit; avoid all skin contact
Isolation: ERG 154: Initial isolation 25m all directions; Protective Action Distance 150m daytime, 300m nighttime for small spills; increase for large spills or fire involvement
— Key Hazards —
• TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury
• 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.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
SOURCE: allfirefighter.com/hazmat/un/1678 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1678 Potassium arsenite Cls6 ERG154 | ERG 154: Initial isolation 25m all directions; Protective Action Distance 150m d | allfirefighter.com/hazmat/un/1678SMS / 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/1678
Advertisement
FAQ
TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury 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 Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas.
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 with SCBA required; impervious gloves and chemical-resistant suit; avoid all skin contact
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 154 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.