Gas Purity Testing

Medical Gas systems deliver gases directly to patients and must therefore be tested for purity. This applies to new systems as well as existing systems which must periodically tested to ensure that all is well. Routine quality control testing of Medical Gases on site is essential for any District/Clinic/General Hospital with a full Piped Medical Gas System or a small medical oxygen installation.

This relates to the purity, quality and identity testing of the Medical quality gases  including surgical air gas, dental air and medical vacuum terminal units (TU’s) or outlets at clinics/hospitals, where required, following guidance given in HTM02-01:2006, EP2009 and EN7396-1:2007.

Responsible persons will liaise with the Authorised Person and hospital staff to connect to the TU’s, NIST or plant sample points and other outlets that can be safely tested during the day’s testing session. Testing is generally undertaken first at plant sample points and then in distal departments.

  • Tests for any particulate matter contamination, using filters connected to the gas outlets. Gas is allowed to pass at a higher rate than would be normally used.
  • Tests for gas identity.
  • Test for gas quality, in particular oxygen purity level, which needs to be checked using a paramagnetic oxygen analyser.
  • Nitrous oxide  readings are taken using a FP99 infra-red analyser.  All readings are to be consistent with the TU gas type and  must have similar readings  to the readings obtained from separate small cylinders or calibration canisters.
  • Carbon monoxide, carbon dioxide, water vapour, Sulphur dioxide, higher oxides of nitrogen will be checked for using detector reagent tubes and a sampling pump.
  • Oil levels are measured using detector tubes and a flow of gas is passed through the reagent tube for two hours.
  • Odour and taste are performed using human organoleptic senses.

Operatives will leave site areas as per hospital protocols.

A conclusive & detailed report is prepared containing results, other observations and constructive comments which will be distributed.