Medical Air : For purposes of this standard, medical air is air supplied from cylinders, bulk containers, medical air compressors, or has been reconstituted from oxygen USP and oil-free, dry nitrogen NF
NFPA 99 Standard for Health Care Facilities, 2002 ed. https://law.resource.org/pub/us/cfr/ibr/004/nfpa.9 9.2005.pdf, (Std: Hlth Care Fcilty - Amer) {242 NFC}