UN 2035 — Refrigerant gas R-143a
Placard: Flammable Gas. ERG Guide 115. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2035 is Refrigerant gas R-143a, a flammable gas entry assigned to ERG Guide 115. The main hazards are ignition, flashback, cylinder rupture and vapor accumulation.
Hazard overview: EXTREMELY FLAMMABLE compressed or liquefied gas; may ignite easily by heat, sparks or flame. Can form explosive mixtures with air and flash back from distant ignition sources. Gas may collect in low or confined areas depending on gas density and ventilation.
Response guidance: For a UN 2035 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 115. 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 2035 should emphasize gas vapor travel, flashback, source isolation, cylinder cooling, BLEVE/rocket hazards and ignition control. Use ERG 115, SDS and local SOP.
Regulatory context: Refrigerant gas R-143a 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: Refrigerant gas R-143a containers should be secured in a cool, ventilated gas storage area away from heat, flames where applicable, physical damage and incompatible materials. Follow SDS and local code for pressure, ventilation and segregation.
UN 2035 Quick Details
Common Hazards of UN 2035
- EXTREMELY FLAMMABLE compressed or liquefied gas; may ignite easily by heat, sparks or flame.
- Can form explosive mixtures with air and flash back from distant ignition sources.
- Gas may collect in low or confined areas depending on gas density and ventilation.
- Cylinders or receptacles exposed to fire may vent, rupture or rocket.
- Contact with rapidly expanding or liquefied gas may cause frostbite or cold burns.
- Fire may produce irritating or toxic decomposition gases depending on product.
- Do not extinguish a leaking gas fire unless the gas flow can be stopped safely.
Chemical Identity & Physical Properties
Colorless, odorless liquefied gas under pressure. Shipped as a liquefied compressed gas.
| Also known as | 1,1,1-TrifluoroethaneHFC-143aTrifluoroethaneMethylfluoroformCF3CH3 |
| CAS Number | 420-46-2 |
| Appearance | Colorless, odorless liquefied gas under pressure. Shipped as a liquefied compressed gas. |
| Flash Point | Not applicable (gas) |
| Boiling Point | -47C (-53F) |
| Vapor Density | 2.9 (heavier than air) |
| Water Reactivity | No significant reaction with water |
Fireground Response Guidance — UN 2035
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for leak, vapor, fire or confined-space exposure. Wear flame-resistant protection and insulated gloves/eye protection where liquefied or rapidly expanding gas contact is possible.
Isolation & Evacuation
First Actions for a UN 2035 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, gas, dust, mist, smoke or fumes and avoid skin or eye contact.
- Eliminate ignition sources if safe and keep vapors and runoff out of drains, sewers, basements and low areas.
- 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 spread, dust spread, cylinder heating or unknown product identity.
- Use ERG Guide 115, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 2035 — Refrigerant gas R-143aUse 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.