UN 2027 — Sodium arsenite, solid
Placard: Toxic. ERG Guide 151. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2027 is Sodium arsenite, solid, a highly toxic arsenic compound assigned to ERG Guide 151. Dust, skin contact and arsenic-contaminated runoff are the main response concerns.
Hazard overview: HIGHLY TOXIC arsenic compound; may be fatal if inhaled, ingested or absorbed through skin. Dust or contaminated solution can spread arsenic contamination to clothing, tools, soil and runoff. Dissolves in water to form toxic arsenic-containing solution; avoid dust generation and uncontrolled runoff.
Response guidance: For a UN 2027 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 151. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff or vapor spread and base entry/fire-control actions on monitoring and local SOP.
Firefighter training notes: Training for UN 2027 should emphasize toxic skin/dust exposure, persistent contamination, decontamination waste, runoff containment and exposure documentation. Use ERG 151, SDS and local SOP.
Regulatory context: Sodium arsenite, solid is regulated as a hazardous material for transportation and emergency response purposes. Storage, workplace exposure, emergency planning, spill reporting, waste handling and environmental requirements vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Sodium arsenite, solid should be stored in tightly closed compatible containers in a secure toxic-material area with secondary containment, restricted access, ventilation and waste/decontamination planning according to SDS.
UN 2027 Quick Details
Common Hazards of UN 2027
- HIGHLY TOXIC arsenic compound; may be fatal if inhaled, ingested or absorbed through skin.
- Dust or contaminated solution can spread arsenic contamination to clothing, tools, soil and runoff.
- Dissolves in water to form toxic arsenic-containing solution; avoid dust generation and uncontrolled runoff.
- Non-combustible, but heating or fire may produce toxic arsenic fumes and irritating gases.
- Runoff may pollute waterways and create persistent contamination.
- Containers may rupture or fail when heated.
- Avoid all skin contact and prevent contaminated dust from becoming airborne.
Chemical Identity & Physical Properties
White to grayish-white crystalline powder or granular solid. Odorless or slight garlic-like odor when impure. Hygroscopic (absorbs moisture from air).
| Also known as | Sodium arseniteArsenous acid sodium saltSodium metaarseniteNatrium arsenitePenite |
| CAS Number | 7784-46-5 |
| Appearance | White to grayish-white crystalline powder or granular solid. Odorless or slight garlic-like odor when impure. Hygroscopic (absorbs moisture from air). |
| Flash Point | Not applicable (non-combustible inorganic salt) |
| Boiling Point | Not applicable (decomposes at high temperature) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Dissolves in water forming toxic alkaline solution; no violent reaction but creates hazardous arsenic-containing solution |
Fireground Response Guidance — UN 2027
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for dust, vapor, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing selected from SDS; avoid skin contact.
Isolation & Evacuation
First Actions for a UN 2027 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, gas, dust, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled/released material unless properly trained and wearing appropriate protective equipment.
- Prevent contaminated dust, liquid, residues, runoff and decontamination waste from spreading.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or release area and expand the perimeter for fire involvement, vapor spread, dust spread, cylinder heating or unknown product identity.
- Use ERG Guide 151, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 2027 — Sodium arsenite, solidUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.