UN 2420 — Hexafluoroacetone
Placard: Toxic Gas. ERG Guide 125. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2420 is Hexafluoroacetone, a toxic corrosive liquefied gas assigned to ERG Guide 125. Inhalation, acid gas formation and frostbite are key concerns.
Hazard overview: TOXIC and CORROSIVE liquefied compressed gas; inhalation may be fatal. Gas or liquefied gas contact can cause chemical burns and frostbite. Vapors may be heavier than air and collect in low or confined areas.
Response guidance: For UN 2420, isolate the release, stay upwind and use SCBA with chemical protection for entry. Monitor air, protect against frostbite/corrosive gas and control runoff from vapor suppression under ERG 125.
Firefighter training notes: Training for UN 2420 should emphasize toxic gas isolation, air monitoring, Level A/SCBA entry, corrosive or oxidizing behavior, frostbite, vapor control and runoff management. Use ERG 125, SDS and local SOP.
Regulatory context: Hexafluoroacetone 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: Hexafluoroacetone cylinders should be secured in a cool, ventilated gas-storage area away from heat, physical damage and incompatible materials. Provide leak detection, ventilation and emergency planning according to SDS and local code.
UN 2420 Quick Details
Common Hazards of UN 2420
- TOXIC and CORROSIVE liquefied compressed gas; inhalation may be fatal.
- Gas or liquefied gas contact can cause chemical burns and frostbite.
- Vapors may be heavier than air and collect in low or confined areas.
- Water or moisture may form corrosive fluoride or acid products depending on the gas.
- Fire or heating may produce irritating, corrosive and/or toxic gases.
- Containers exposed to fire may vent, rupture or rocket.
- Runoff from vapor control or fire water may become corrosive and toxic.
Chemical Identity & Physical Properties
Colorless gas with a pungent, musty odor. Shipped as a liquefied compressed gas. Heavier than air.
| Also known as | HFA1,1,1,3,3,3-Hexafluoro-2-propanonePerfluoroacetoneHexafluoropropanone |
| CAS Number | 684-16-2 |
| Appearance | Colorless gas with a pungent, musty odor. Shipped as a liquefied compressed gas. Heavier than air. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | -28°C (-18°F) |
| Vapor Density | 7.2 (heavier than air) |
| Water Reactivity | Reacts with water forming hydrates; reaction is exothermic but not violent |
Fireground Response Guidance — UN 2420
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and fully encapsulating chemical protective clothing for close entry or unknown concentrations. Protect against corrosive gas and liquefied-gas frostbite.
Isolation & Evacuation
First Actions for a UN 2420 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind and keep people out of low or poorly ventilated areas.
- Treat the release as an inhalation hazard until monitoring proves otherwise.
- Do not touch leaking cylinders or liquefied gas without proper training and PPE.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 125, SDS, cylinder markings and air monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2420 — HexafluoroacetoneUse 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.