UN 2198 — Phosphorus pentafluoride, compressed
Placard: Toxic Gas. ERG Guide 125. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2198 is Phosphorus pentafluoride, compressed, a toxic corrosive fluoride gas assigned to ERG Guide 125. Moisture can form hydrogen fluoride or related corrosive products.
Hazard overview: TOXIC and CORROSIVE compressed gas; inhalation may be fatal or cause severe respiratory injury. May react with moisture to form hydrogen fluoride and metal/nonmetal oxide or acid products. Gas or liquefied gas contact may cause chemical burns and/or frostbite.
Response guidance: For a UN 2198 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 125. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff or vapor spread and base entry/fire-control actions on monitoring and local SOP.
Firefighter training notes: Training for UN 2198 should emphasize toxic/corrosive gas isolation, moisture or fluoride acid formation, air monitoring, Level A entry decisions, decontamination and downwind protection. Use ERG 125, SDS and local SOP.
Regulatory context: Phosphorus pentafluoride, compressed is regulated as a hazardous material for transportation and emergency response purposes. Storage, workplace exposure, emergency planning, spill reporting, waste handling and environmental requirements vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Phosphorus pentafluoride, compressed containers should be secured in a cool, ventilated gas storage area away from heat, physical damage and incompatible materials. Toxic, flammable, oxidizing, corrosive or refrigerated gases require leak detection/ventilation and emergency planning according to SDS and local code.
UN 2198 Quick Details
Common Hazards of UN 2198
- TOXIC and CORROSIVE compressed gas; inhalation may be fatal or cause severe respiratory injury.
- May react with moisture to form hydrogen fluoride and metal/nonmetal oxide or acid products.
- Gas or liquefied gas contact may cause chemical burns and/or frostbite.
- Heavy gas may collect in low or confined areas.
- Fire or heat may produce irritating, corrosive and/or toxic fluoride gases.
- Containers may rupture or rocket when heated.
- Runoff or water contact may spread corrosive fluoride contamination.
Chemical Identity & Physical Properties
Colorless gas with a pungent, irritating odor. Fumes in moist air. Exists as a compressed gas at room temperature.
| Also known as | Phosphorus(V) fluoridePentafluorophosphorusPentafluorophosphoranePF5 |
| CAS Number | 7647-19-0 |
| Appearance | Colorless gas with a pungent, irritating odor. Fumes in moist air. Exists as a compressed gas at room temperature. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | -84.6C (-120.3F) |
| Vapor Density | 4.3 (heavier than air) |
| Water Reactivity | Reacts violently with water producing toxic and corrosive hydrogen fluoride gas and phosphoric acid. Keep dry. |
Fireground Response Guidance — UN 2198
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and fully encapsulating chemical protective clothing for close entry or unknown concentrations. Level A may be needed; protect against frostbite where liquefied gas contact is possible.
Isolation & Evacuation
First Actions for a UN 2198 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.
- Treat the release as a serious inhalation hazard and consider downwind protective actions using ERG and monitoring.
- Avoid breathing gas, vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Avoid unnecessary water contact with the released product unless incident command confirms a compatible vapor-control use.
- Do not touch damaged containers or spilled/released 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 release area and expand the perimeter for fire involvement, vapor/gas spread, cylinder heating, oxidizer reaction or unknown product identity.
- Use ERG Guide 125, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 2198 — Phosphorus pentafluoride, compressedUse 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.