40 CFR 98.302: GHGs to report.

You must report emissions of each fluorinated GHG, including but not limited to SF6 and PFCs, from your facility (including emissions from fugitive equipment leaks, installation, servicing, equipment decommissioning and disposal, and from storage cylinders) resulting from the transmission and distribution servicing inventory and equipment listed in § 98.300(a), except you are not required to report emissions of fluorinated GHGs that are components of insulating gases whose weighted average GWPs, as calculated in equation DD-3 to this section, are less than or equal to one. For acquisitions of equipment containing or insulated with fluorinated GHGs, you must report emissions from the equipment after the title to the equipment is transferred to the electric power transmission or distribution entity.

Where:

GWPj = Weighted average GWP of insulating gas j.

GHGi,w = The weight fraction of GHG i in insulating gas j, expressed as a decimal. fraction. If GHG i is not part of a gas mixture, use a value of 1.0.

GWPi = Gas-appropriate GWP as provided in table A-1 to subpart A of this part.

i = GHG contained in the electrical transmission and distribution equipment.