Office of Research: Environmental Health and Safety

Sulfur Hexaflouride

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Due to its extreme global warming potential, the California Air Resources Board (CARB) passed a regulation restricting Sulfur Hexafluoride (SF6) gas emissions, pursuant to the California Global Warning Solutions Act of 2006. This rule places a ban on the sale, use, and release of SF6 for processes not specifically exempted in Title 17, section 95341 of the California Code of Regulations (17 CCR 95341).

Exemptions to this ban that may apply to UCSF operations include:

  • Use as an arc quenching medium in equipment.
  • Use during one-time laboratory variable air volume fume hood certifications, pursuant to 8 CCR 5154.1(c)(2)(B).
  • Medical uses, which include the following applications:
    • Injection or other entry of SF6 into a human or other animal body for the purpose of improving health;
    • Use of SF6 in a diagnostic tool in order to either identify a disease or condition by its outward signs and symptoms or analyze the underlying physiological/biological cause(s) of a disease or condition; and
    • Use of SF6 in a medical treatment process for a disease other than a medical condition.
  • Use in equipment calibration and in testing to find alternatives to sulfur hexafluoride use.
  • Use for research in a research facility. Research facilities planning to use SF6 for on or off-site research in a use not covered by 17 CCR 95341(a)(1-9) must:
    • Register with CARB in the form of a letter to the Executive Officer prior to use and
    • Monitor and report usage annually

Additionally, users and purchasers of SF6 are now required to keep records showing the annual quantity of SF6 used and purchased, beginning March 30, 2010. This requirement applies to all SF6 purchases, whether your operation is exempted or not. SF6 records will be collected by OEH&S and an annual report issued to CARB.

If your research / operation currently use SF6, review the final regulation at or contact UCSF Environmental Programs immediately to determine if you qualify for an exemption.