ISO 18082:2014 specifies the dimensions, the allocation and marking of non-interchangeable screw-threaded (NIST) connectors intended to be used at operating pressures up to 1 400 kPa, and for vacuum systems at pressures not greater than 60 kPa absolute.
ISO 18082:2014 specifies NIST connectors intended for use with the following medical gases:

oxygen,
nitrous oxide,
medical air,
helium,
carbon dioxide,
xenon,
specified mixtures of the gases listed above,
oxygen-enriched air,
air for driving surgical tools,
nitrogen for driving surgical tools,
use with vacuum.