UN 2857 — Refrigerating machines, containing non-flammable, non-poisonous gases
Placard: Non-Flammable Gas. ERG Guide 126. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2857 At a Glance
UN 2857 (Refrigerating machines, containing non-flammable, non-poisonous gases) is listed as DOT Class 2 Non-Flammable Gas and is assigned to ERG Guide 126. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
Refrigerating machines, containing non-flammable, non-poisonous gases are equipment articles containing nonflammable, nonpoisonous refrigerant gas. The main response issues are pressure, asphyxiation, frostbite, and decomposition products in fire.
Hazard overview: An intact unit may pose little immediate hazard, but a leaking unit in a confined space can reduce oxygen without warning. Fire exposure can heat cylinders and produce irritating decomposition gases.
Response guidance: Isolate leaking or fire-exposed units, ventilate only with monitoring, and cool exposed containers from a protected position. Confirm the refrigerant type from the unit label or shipping documents.
Firefighter training notes: Training should cover refrigerant identification, oxygen monitoring, confined-space entry, frostbite precautions, ventilation, and cylinder-heating hazards for UN 2857.
Regulatory context: Confirm the equipment label, refrigerant type, SDS/service documentation, shipping papers, and ERG 126 before final response decisions.
Storage & handling: Keep units upright and protected from heat, impact, and puncture; ensure ventilation and do not store damaged leaking equipment in occupied spaces.
UN 2857 Quick Details
Common Hazards of UN 2857
- Contains compressed or liquefied nonflammable, nonpoisonous refrigerant gas.
- Gas release can displace oxygen, especially in machinery rooms, vehicles, or confined spaces.
- Liquefied gas contact can cause frostbite or cold burns.
- Heated equipment or cylinders can rupture; ruptured cylinders may rocket.
- Most refrigerant vapors are heavier than air and can collect near floors.
- Fire can decompose some refrigerants into irritating or toxic gases.
- Exact refrigerant type must be confirmed from labels, SDS, or service documents.
Chemical Identity & Physical Properties
Mechanical devices containing non-flammable, non-poisonous compressed gases (typically HFCs, HCFCs, or inert gases) as refrigerants. Equipment may be white, gray, or metallic in appearance
| Also known as | Refrigerator unitsCooling equipmentRefrigeration appliancesAir conditioning units with refrigerant |
| Appearance | Mechanical devices containing non-flammable, non-poisonous compressed gases (typically HFCs, HCFCs, or inert gases) as refrigerants. Equipment may be white, gray, or metallic in appearance. |
| Flash Point | Not applicable (non-flammable gases) |
| Boiling Point | Varies by refrigerant gas used; typically -40C to -26C (-40F to -15F) for common refrigerants |
| Vapor Density | Heavier than air for most refrigerant gases (3-5 times air density) |
| Water Reactivity | No significant reaction with water |
Fireground Response Guidance — UN 2857
Extinguishing Media
PPE Requirements
Intact units may require standard PPE. Use SCBA and atmospheric monitoring for leaks, fire exposure, confined spaces, or oxygen-deficient areas.
Isolation & Evacuation
First Actions for a UN 2857 Incident
- Call 911 and the emergency response number shown on shipping papers or equipment documentation.
- Keep unauthorized personnel away and isolate the release area.
- Stay upwind and out of low or confined areas where refrigerant gas may displace oxygen.
- Avoid direct contact with escaping gas or liquid refrigerant because frostbite injury is possible.
- Do not enter machinery rooms, trailers, or confined spaces without SCBA and atmospheric monitoring.
- Ventilate only after ignition, oxygen, and toxic decomposition hazards have been evaluated.
- Use ERG 126, SDS/refrigerant label data, and monitoring results for final protective actions.
📋 Copy & Share Field Card
UN 2857 — Refrigerating machines, containing non-fUse 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.