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3299

UN 3299Ethylene oxide and tetrafluoroethane mixture with not more than 5.6 percent ethylene oxide

Division 2.2

Non-flammable, non-toxic gases

Summary

UN 3299 is the UN number for ethylene oxide and tetrafluoroethane mixture with not more than 5.6 percent ethylene oxide. It is classed in Division 2.2 (non-flammable, non-toxic gases) of Class 2 for transport. Emergency responders use ERG guide 126.

Emergency response

The Emergency Response Guidebook (ERG2024) guide for this number:

  • Guide126Ethylene oxide and tetrafluoroethane mixture, with not more than 5.6% ethylene oxide

From the 2024 Emergency Response Guidebook (ERG2024), published by U.S. Department of Transportation, PHMSA. Read the full guide in the ERG or on CAMEO Chemicals.

Identification

UN number
UN 3299
Name
Ethylene oxide and tetrafluoroethane mixture with not more than 5.6 percent ethylene oxide
Hazard class
Class 2: Gases
Division
2.2: Non-flammable, non-toxic gases
What the class covers
Gases which are neither flammable nor toxic, including asphyxiant and oxidizing gases.

U.S. Hazardous Materials Table

The entry for this number in 49 CFR 172.101.

  • UN3299Ethylene oxide and tetrafluoroethane mixture

    with not more than 5.6 percent ethylene oxide

    Special provisions: T50

    Class
    2.2
    Packing group
    None
    Labels
    2.2

From the eCFR edition of 49 CFR 172.101 dated 2026-10-05 (section last amended 2026-09-08). The eCFR is an editorial compilation, not the official legal edition. Read the current table.

About Class 2

Class 2 covers gases, whether compressed, liquefied, dissolved under pressure or refrigerated. Division 2.1 is flammable gases such as propane, 2.2 is non-flammable, non-toxic gases such as nitrogen, and 2.3 is toxic gases such as chlorine.

See all Class 2 UN numbers

Check the official sources

For emergency response, packaging and quantity limits, use these: