According to European Pharmacopeia, the medicinal air is defined as :

' The medicinal air is compressed air with an oxygen value comprised between 20,4% minimum and 21,4% v/v maximum.'

 

  
Responsability
The hospital pharmacist is responsible for the delivery of the gas with the status of medical device, as well as a drug. He is responsible for the quality of the gas that will be administered to the patient. The gas quality may be altered gas between the gas source (for example a bottle) and the point of use. It is therefore necessary, the pharmacist checks the quality of gas  at regular intervals, at the point of delivery to the patient.
A check should be done after each new installation or modification as well as in routine at an interval to be determined by the pharmacist.

Legal aspect :
-European Directive 93/42/EEG concerning medical devices.
That means:
-A mandatory control (pharmacopoeia analysis) should be performed after each new installation or extension (medical gases) as well as routine assessment by the pharmacist. In most cases, minimum 1 per year (2 samples) on all networks.

Air specification according to the air medicinal monograph:

Physico-chemical analyzes by EP monograph medicinal air (1238: 01/2008)
 

O2 value	20,4%-21,4% ( v/v)
H2O value (Dew point)*	≤67 ppm v/v ou ≤-40°C
CO2 value	≤500 ppm v/v
CO value	≤ 15 ppm v/v
COV value	≤ 0,1 mg/m3
NO value	≤2 ppm v/v
NO2 value	≤ 2 ppm v/v
SO2 value	≤1 ppm v/v