UN 2674 — Sodium fluorosilicate
Placard: Toxic. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2674 At a Glance
UN 2674 (Sodium fluorosilicate) is listed as DOT Class 6 Toxic and is assigned to ERG Guide 154. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.