UN 2473 — Sodium arsanilate
Placard: Toxic. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2473 is Sodium arsanilate, a toxic arsenic compound assigned to ERG Guide 154. Dust, runoff and secondary contamination are key response concerns.
Hazard overview: TOXIC arsenic compound; inhalation, ingestion or skin contact may cause serious poisoning. Dust or solution can contaminate clothing, tools, soil and runoff. Non-combustible or combustible behavior depends on formulation, but fire can produce toxic arsenic fumes.
Response guidance: For UN 2473, isolate the area, avoid skin contact and use SCBA where vapor, dust, gas or fire is present. Control ignition or contamination hazards and contain runoff using SDS and ERG 154.
Firefighter training notes: Training for UN 2473 should emphasize exposure routes, SCBA use, vapor/dust monitoring, fire behavior, decontamination, runoff containment and SDS verification. Use ERG 154, SDS and local SOP.
Regulatory context: Sodium arsanilate is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Sodium arsanilate should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 2473 Quick Details
Common Hazards of UN 2473
- TOXIC arsenic compound; inhalation, ingestion or skin contact may cause serious poisoning.
- Dust or solution can contaminate clothing, tools, soil and runoff.
- Non-combustible or combustible behavior depends on formulation, but fire can produce toxic arsenic fumes.
- Avoid dust generation and secondary contamination.
- Runoff may carry persistent arsenic contamination and harm waterways.
- Containers may rupture or fail when heated.
- Medical evaluation and controlled decontamination may be needed after exposure.
Chemical Identity & Physical Properties
White to grayish-white crystalline powder or granular solid. Odorless. Soluble in water.
| Also known as | Arsanilic acid sodium saltSodium 4-aminophenylarsonateSodium p-arsanilate4-Aminophenylarsonic acid sodium salt |
| CAS Number | 127-85-5 |
| Appearance | White to grayish-white crystalline powder or granular solid. Odorless. Soluble in water. |
| Flash Point | Not applicable (non-combustible solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water; forms toxic solutions but no violent reaction |
Fireground Response Guidance — UN 2473
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for dust, vapor, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2473 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream.
- Avoid breathing vapor, dust, gas, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated dust, liquid, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 154, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2473 — Sodium arsanilateUse 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.