Section 98.300 - Definition of the source category(a) The electrical transmission and distribution equipment use source category consists of all electric transmission and distribution equipment and servicing inventory insulated with or containing sulfur hexafluoride (SF6 ) or perfluorocarbons (PFCs) used within an electric power system. Electric transmission and distribution equipment and servicing inventory includes, but is not limited to:(1) Gas-insulated substations.(3) Switchgear, including closed-pressure and hermetically sealed-pressure switchgear and gas-insulated lines containing SF6 or PFCs.(4) Gas containers such as pressurized cylinders.(6) Electric power transformers.(7) Other containers of SF6 or PFC.