UN 3057 — Trifluoroacetyl chloride
Placard: Toxic Gas. ERG Guide 125. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3057 is Trifluoroacetyl chloride, a toxic corrosive liquefied acid chloride gas assigned to ERG Guide 125. Moisture reaction and low-area vapor are key hazards.
Hazard overview: TOXIC and CORROSIVE liquefied acid chloride gas; inhalation may be fatal. Reacts violently with water or moist air, releasing hydrogen chloride, hydrogen fluoride-containing products and heat. Gas or liquefied gas can burn eyes, skin and respiratory tissue; liquefied gas may also cause frostbite.
Response guidance: For UN 3057, isolate downwind/low areas, use SCBA with chemical protection and cool cylinders from a protected position. Control reactive/corrosive runoff under ERG 125.
Firefighter training notes: Training for UN 3057 should emphasize exposure routes, SCBA use, vapor/dust monitoring, decontamination, runoff containment and SDS/package verification. Use ERG 125, SDS and local SOP.
Regulatory context: Trifluoroacetyl chloride is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Trifluoroacetyl chloride should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 3057 Quick Details
Common Hazards of UN 3057
- TOXIC and CORROSIVE liquefied acid chloride gas; inhalation may be fatal.
- Reacts violently with water or moist air, releasing hydrogen chloride, hydrogen fluoride-containing products and heat.
- Gas or liquefied gas can burn eyes, skin and respiratory tissue; liquefied gas may also cause frostbite.
- Vapors from liquefied gas are initially heavier than air and can spread along the ground.
- Containers exposed to fire may vent, rupture or rocket.
- Fire may produce corrosive/toxic acid gases and fluorinated smoke.
- Runoff or vapor-control water may be acidic, fluoride-contaminated and toxic.
Chemical Identity & Physical Properties
Colorless to pale yellow fuming liquid with a pungent, acrid odor. Fumes heavily in moist air due to reaction with water vapor.
| Also known as | Trifluoroacetyl chlorideTFACTrifluoroacetic acid chlorideTrifluoroethanoyl chloride |
| CAS Number | 354-32-5 |
| Appearance | Colorless to pale yellow fuming liquid with a pungent, acrid odor. Fumes heavily in moist air due to reaction with water vapor. |
| Flash Point | Not applicable (non-flammable) |
| Boiling Point | -28C (-18F) |
| Vapor Density | 4.6 (heavier than air) |
| Water Reactivity | Reacts violently with water, producing corrosive hydrofluoric acid and trifluoroacetic acid vapors; do not use water directly on material |
Fireground Response Guidance — UN 3057
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and fully encapsulating chemical protective clothing for significant releases. Protect against toxic corrosive gas and liquefied-gas frostbite.
Isolation & Evacuation
First Actions for a UN 3057 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, gas, mist, smoke or fumes and avoid skin or eye contact.
- Keep water or moisture contact controlled when it may increase fuming, heat or corrosive runoff.
- Do not touch damaged containers 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 125, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3057 — Trifluoroacetyl chlorideUse 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.