40 CFR § 98.458 - Definitions.

---
identifier: "/us/cfr/t40/s98.458"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 98.458 - Definitions."
title_number: 40
title_name: "Protection of Environment"
section_number: "98.458"
section_name: "Definitions."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "98"
part_name: "MANDATORY GREENHOUSE GAS REPORTING"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401-7671q."
regulatory_source: "74 FR 56374, Oct. 30, 2009, unless otherwise noted."
cfr_part: "98"
---


# 98.458 Definitions.

Except as specified in this section, all terms used in this subpart have the same meaning given in the CAA and subpart A of this part.

*Insulating gas*, for the purposes of this subpart, means any fluorinated GHG or fluorinated GHG mixture, including but not limited to SF<sub>6</sub> and PFCs, that is used as an insulating and/or arc-quenching gas in electrical equipment.

*Reportable insulating gas*, for purposes of this subpart, means an insulating gas whose weighted average GWP, as calculated in equation SS-2 to § 98.452, is greater than one. A fluorinated GHG that makes up either part or all of a reportable insulating gas is considered to be a component of the reportable insulating gas.