UN 2853 — Magnesium fluorosilicate
Placard: Toxic. ERG Guide 151. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Magnesium fluorosilicate is a toxic fluorosilicate material, usually encountered as a crystalline powder or granular solid. Response should control dust, prevent runoff, and account for fluoride exposure risk.
Hazard overview: The material is not a fire fuel, but Magnesium fluorosilicate can create toxic dust and acidic fluoride-containing solutions. Heating can increase corrosive fluoride fume concerns.
Response guidance: Isolate the spill, minimize dust, and keep material out of watercourses. Use water spray only where runoff can be contained, and use compatible agents for surrounding fires.
Firefighter training notes: Training should cover toxic dust/vapor control, decontamination, runoff containment, respiratory protection, and SDS-based exposure precautions for UN 2853.
Regulatory context: Confirm the exact shipping description, hazard class, packaging, SDS, and ERG 151; disposal and cleanup may require hazardous-waste controls.
Storage & handling: Store tightly closed in a dry, labeled area away from food, incompatible materials, and conditions that could spread dust, vapor, or contaminated runoff.
UN 2853 Quick Details
Common Hazards of UN 2853
- Toxic fluorosilicate solid; inhalation, ingestion, or skin contact can cause serious injury.
- Dust can irritate or damage the respiratory tract, eyes, and skin.
- Water can form acidic fluoride-containing solutions; runoff remains toxic.
- Heating or fire may release toxic and corrosive fluoride fumes.
- Nonflammable itself, but containers may fail in fire exposure.
- Avoid high-pressure water or air movement that disperses powder.
- Exact compound and concentration should be verified from SDS and shipping papers.
Chemical Identity & Physical Properties
White to off-white crystalline powder or granular solid. Odorless. Soluble in water
| Also known as | Magnesium hexafluorosilicateMagnesium silicofluorideSilicic acid magnesium saltMagnesium fluosilicate |
| CAS Number | 16949-65-8 |
| Appearance | White to off-white crystalline powder or granular solid. Odorless. Soluble in water. |
| Flash Point | Not applicable (inorganic solid, non-flammable) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid, no vapor pressure) |
| Water Reactivity | Soluble in water, forms acidic solution; releases hydrogen fluoride gas upon heating in moist conditions |
Fireground Response Guidance — UN 2853
Extinguishing Media
PPE Requirements
Use SCBA or appropriate full-face respiratory protection with chemical-resistant suit, gloves, boots, and eye/face protection.
Isolation & Evacuation
First Actions for a UN 2853 Incident
- Call 911 and the emergency response number shown on shipping papers or the SDS.
- Keep unauthorized personnel away and prevent dust, vapor, or runoff from spreading.
- Stay upwind, uphill, and upstream; avoid breathing dust, fumes, or fire gases.
- Avoid all skin and eye contact with powder, liquid, solutions, or contaminated clothing.
- Do not touch damaged containers or spilled material without chemical-resistant PPE.
- Control runoff and keep material out of drains, soil, and waterways.
- Use ERG guidance, SDS, shipping papers, and exposure monitoring before cleanup.
📋 Copy & Share Field Card
UN 2853 — Magnesium 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.