Oxygen

NFPA 99 designation color: green background / white letters or white background with green letters
standard gauge pressure: 50 to 55 psig (345 to 380 kPa)
properties: atomic number 8, atomic weight 15.9994, tasteless / colorless / odorless, approx 21% of the atmosphere
uses: respiratory and inhalation therapy, used in conjunction with anesthesia machines

Medical Air

NFPA 99 designation color: yellow background / black letters
standard gauge pressure: 50 to 55 psig (345 to 380 kPa)
properties: air consists of the approx gaseous volumes - 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.03% carbon dioxide, and minute traces of neon, helium, methane, krypton, hydrogen, xenon, and ozone
uses: respiratory therapy, drive ventilators, reduction of high oxygen concentrations

Medical / Surgical Vacuum

NFPA 99 designation color: white background / black letters
standard gauge pressure: 15" to 30" Hg (380 to 760 mm)
properties: result of pressure being less than atmospheric. 0" Hg gauge = atmospheric pressure (i.e. 0 vacuum) while 30" Hg gauge = perfect vacuum
uses: assists in draining fluids and tissue from patients. The medical vacuum infrastructure is designed to remain dry!

Nitrogen

NFPA 99 designation color: black background / white letters
standard gauge pressure: 160 to 185 psig (1100 to 1275 kPa)
properties: atomic number 7, atomic weight 14.0067, colorless / odorless, approx 78% of the atmosphere
uses: power pneumatic tools

Nitrous Oxide (also called laughing gas)

NFPA 99 designation color: blue background / white letters
standard gauge pressure: 50 to 55 psig (345 to 380 kPa)
properties: colorless with sweetish taste and odor, supports combustion
uses: analgesic agent (diverse group of drugs used to relieve pain), used in anesthesia

Carbon Dioxide

NFPA 99 designation color: gray background / black letters or gray background / white letters
standard gauge pressure: 160 to 185 psig (1100 to 1275 kPa)
properties: colorless / odorless / tasteless, approx 0.03% of the atmosphere, does not support combustion (other than when combined with magnesium)
uses: stimulates respiration,  used in insufflation (expands a body cavity by blowing carbon dioxode into it)

WAGD (Waste Anesthetic Gas Disposal)

NFPA 99 designation color: violet background / white letters
standard gauge pressure: can vary with the system type used
properties: result of pressure being less than atmospheric. 0" Hg gauge = atmospheric pressure (i.e. 0 vacuum) while 30" Hg gauge = perfect vacuum
uses: removal of anesthesia gases expelled from a patient

Instrument Air

NFPA 99 designation color: red background / white letters
standard gauge pressure: 160 to 185 psig (1100 to 1275 kPa)
properties: air consists of the approx gaseous volumes - 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.03% carbon dioxide, and minute traces of neon, helium, methane, krypton, hydrogen, xenon, and ozone
uses: power pneumatic tools