UN 2674 — Sodium fluorosilicate
Placard: Toxic. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2674 is Sodium fluorosilicate, a toxic fluoride/silicate salt assigned to ERG Guide 154. Dust and fluoride-contaminated runoff are key hazards.
Hazard overview: TOXIC fluoride/silicate salt; inhalation of dust, ingestion or skin contact may cause severe injury. Dust can irritate or burn eyes, skin and respiratory tissue. Non-combustible solid, but heating can release toxic/corrosive fluoride fumes.
Response guidance: For UN 2674, isolate the area, avoid skin contact and use SCBA where dust, vapor, mist or fire is present. Control ignition or moisture hazards as applicable and contain toxic/corrosive runoff.
Firefighter training notes: Training for UN 2674 should emphasize toxic exposure routes, SCBA use, dust/vapor monitoring, fire behavior, decontamination, runoff containment and SDS verification. Use ERG 154, SDS and local SOP.
Regulatory context: Sodium fluorosilicate 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 fluorosilicate should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 2674 Quick Details
Common Hazards of UN 2674
- TOXIC fluoride/silicate salt; inhalation of dust, ingestion or skin contact may cause severe injury.
- Dust can irritate or burn eyes, skin and respiratory tissue.
- Non-combustible solid, but heating can release toxic/corrosive fluoride fumes.
- Acid contact can release hydrogen fluoride-containing vapors or acidic fluoride solution.
- Runoff may be fluoride-contaminated and harmful to waterways.
- Avoid dust generation and secondary contamination of PPE or tools.
- Containers may fail when heated.
Chemical Identity & Physical Properties
White odorless crystalline powder or granular solid at room temperature. May appear as small crystals or dust.
| Also known as | Disodium hexafluorosilicateDisodium silicon hexafluorideSodium silicofluorideSalufer |
| CAS Number | 16893-85-9 |
| Appearance | White odorless crystalline powder or granular solid at room temperature. May appear as small crystals or dust. |
| Flash Point | Not applicable (non-combustible inorganic solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid, non-volatile at ambient conditions) |
| Water Reactivity | Slowly soluble in water; hydrolyzes to release hydrofluoric acid in acidic conditions. Avoid contact with acids. |
Fireground Response Guidance — UN 2674
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 2674 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, 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 liquid, dust, 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 2674 — Sodium fluorosilicateUse 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.