ISO 9170-1:2008 applies to: terminal units intended for use in medical gas pipeline systems in accordance with ISO 7396-1, for use with the following medical gases: oxygen, nitrous oxide; medical air; carbon dioxide; oxygen/nitrous oxide mixture [50 %/50 % (by volume)]; terminal units intended for use in medical gas pipeline systems in accordance with ISO 7396-1, for use with the following gases and services: oxygen-enriched air; air for driving surgical tools; nitrogen for driving surgical tools; vacuum. It is intended especially to ensure the gas-specific assembly of terminal units and to prevent their interchange between different gases and services. ISO 9170-1:2008 specifies requirements for terminal units for supply and disposal of nitrogen or air for driving surgical tools and requirements for probes intended to be connected to the gas-specific connection point which is part of the terminal unit.