Inert Gas 11 : For the purpose of handling releases of flammable and combustible liquids and gases, a gas that is nonflammable, chemically inactive, noncontaminating for the use intended, and oxygen-deficient to the extent required
NFPA 329 Recommended Practice for Handling Releases of Flammable and Combustible Liquids and Gases, 2005 ed. https://www.nfpa.org/assets/files/AboutTheCodes/32 9/329-F2009-ROP.pdf, (Recmm Prac: Hndlg Releases of Flamm and Comb Liqd and Gas - Amer) {299 NFC}