---
kind: "section"
citation: "40 C.F.R. § 98.208"
title: "40"
number: "98.208"
heading: "Definitions."
url: "https://uscodex.org/cfr/40/98.208"
---

# §98.208. Definitions.


All terms used in this subpart have the same meaning given in the Clean Air Act and subpart A of this part. Additionally, some sector-specific definitions are provided below:

Carrier gas means the gas with which cover gas is mixed to transport and dilute the cover gas thus maximizing its efficient use. Carrier gases typically include CO2, N2, and/or dry air.

Cover gas means SF6, HFC-134a, fluorinated ketone (FK 5-1-12) or other gas used to protect the surface of molten magnesium from rapid oxidation and burning in the presence of air. The molten magnesium may be the surface of a casting or ingot production operation or the surface of a crucible of molten magnesium that feeds a casting operation.


## Notes

### Source

Source: 75 FR 39761, July 12, 2010, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.