UN 1768 — Difluorophosphoric acid, anhydrous
Placard: Corrosive. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1768 is Difluorophosphoric acid, anhydrous, a toxic corrosive fluorinated acid assigned to ERG Guide 154. Moisture can generate heat and corrosive fluoride/phosphate contamination.
Hazard overview: UN 1768 presents toxic/corrosive acid, fluoride fume, moisture-reaction and contaminated-runoff hazards. Avoid direct water contact with product unless incident command confirms a safe control method.
Response guidance: For a UN 1768 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 154. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1768 should emphasize corrosive exposure routes, water or oxidizer incompatibility where applicable, air monitoring, PPE selection, decontamination and runoff containment. Use ERG 154, SDS and local SOP.
Regulatory context: Difluorophosphoric acid, anhydrous is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, pesticide/waste handling where applicable, storage and environmental requirements may vary by formulation, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Difluorophosphoric acid, anhydrous should be stored in tightly closed compatible containers in a cool, dry, well-ventilated area away from water, moisture, bases, oxidizers/reducing agents where incompatible, heat and unauthorized access. Protect containers from corrosion, leakage and contamination.
UN 1768 Quick Details
Common Hazards of UN 1768
- TOXIC and CORROSIVE fluorinated phosphoric acid; inhalation, ingestion or contact may cause severe injury.
- Moisture or water can release heat and acidic fluoride/phosphoric acid fumes or solution.
- Dust, mist or vapor can severely irritate or burn eyes, skin and respiratory tissue.
- Heating or fire may produce toxic/corrosive fluoride and phosphorus oxide gases.
- Runoff may carry corrosive fluoride/phosphate contamination.
- Containers may rupture or fail when heated.
- Avoid all skin contact and control runoff.
Chemical Identity & Physical Properties
Colorless to pale yellow fuming liquid with a pungent, acidic odor. Highly corrosive and releases irritating fumes in moist air.
| Also known as | Difluorophosphoric acidPhosphorodifluoridic acidDFP acidHydrogen difluorophosphate |
| CAS Number | 13779-41-4 |
| Appearance | Colorless to pale yellow fuming liquid with a pungent, acidic odor. Highly corrosive and releases irritating fumes in moist air. |
| Flash Point | Not applicable (non-flammable) |
| Boiling Point | 116C (241F) |
| Vapor Density | 3.5 (heavier than air) |
| Water Reactivity | Reacts with water releasing heat and forming corrosive phosphoric acid solutions; hydrolyzes in moisture |
Fireground Response Guidance — UN 1768
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fume, fire or confined-space exposure. Chemical-resistant gloves, boots, eye/face protection and protective clothing should be selected from SDS; Level A may be needed for close entry or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 1768 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, fumes, dust, mist or spray and avoid skin or eye contact.
- Keep water and moisture away from released product unless incident command confirms a compatible cooling or control use.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if vapor, dust, fire involvement, water reaction or unknown concentration is present.
- Use ERG Guide 154, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1768 — Difluorophosphoric acid, anhydrousUse 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.