UN 3471 — Hydrogendifluorides, solution, n.o.s.
Placard: Corrosive. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3471 At a Glance
UN 3471 (Hydrogendifluorides, solution) is listed as DOT Class 8 Corrosive 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 3471 is Hydrogendifluorides, solution, n.o.s., a corrosive fluoride solution assigned to ERG Guide 154. Fluoride burns, HF fumes and contaminated runoff are key concerns.
Hazard overview: CORROSIVE fluoride solution, n.o.s.; contact can severely burn skin, eyes and respiratory tissue. Fluoride exposure can cause deep tissue injury and systemic toxicity depending on concentration. Acids or heat may release hydrogen fluoride-containing fumes.
Response guidance: For UN 3471, isolate the spill, avoid fuming dust/mist and use SCBA with acid/fluoride protection. Control water reaction and runoff under ERG 154.
Firefighter training notes: Training for UN 3471 should emphasize exposure routes, SCBA use, vapor/dust monitoring, decontamination, runoff containment and SDS verification. Use ERG 154, SDS and local SOP.
Regulatory context: Hydrogendifluorides, solution, n.o.s. is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, concentration, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Hydrogendifluorides, solution, n.o.s. should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 3471 Quick Details
Common Hazards of UN 3471
- CORROSIVE fluoride solution, n.o.s.; contact can severely burn skin, eyes and respiratory tissue.
- Fluoride exposure can cause deep tissue injury and systemic toxicity depending on concentration.
- Acids or heat may release hydrogen fluoride-containing fumes.
- Solution may react with glass, metals or incompatible materials depending on composition.
- Fire may produce toxic/corrosive fluoride fumes.
- Runoff may be acidic/fluoride-contaminated and harmful to waterways.
- Exact hydrogendifluoride salt, concentration and pH must be verified from SDS.
Chemical Identity & Physical Properties
Clear to slightly colored aqueous solution with a pungent, irritating odor. Highly corrosive liquid at room temperature.
| Also known as | Bifluoride solutionAcid fluoride solutionHydrogen difluoride solutionHF2- solutionSodium hydrogen difluoride solutionPotassium hydrogen difluoride solution |
| Appearance | Clear to slightly colored aqueous solution with a pungent, irritating odor. Highly corrosive liquid at room temperature. |
| Flash Point | Not applicable (aqueous solution, non-flammable) |
| Boiling Point | Approximately 100-110C (212-230F) depending on concentration |
| Vapor Density | Not applicable (aqueous solution, vapors heavier than air if HF released) |
| Water Reactivity | Already in aqueous solution; dilution with water generates heat and may release hydrogen fluoride vapor |
Fireground Response Guidance — UN 3471
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and acid/fluoride-resistant chemical protective clothing. Level A may be needed for fuming, splash or unknown concentration.
Isolation & Evacuation
First Actions for a UN 3471 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.
- Keep water, acids/bases or incompatible materials controlled until product-specific guidance is confirmed.
- Do not touch damaged containers, equipment 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 3471 — Hydrogendifluorides, solution, n.o.s.Use 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.