Steam & Water Quality Testing

The lifespan of an autoclave can be significantly affected by the quality of water used. To maintain an autoclave to a high standard, quality checks on the water source must also be completed periodically. 

Effective steam sterilization relies on continuous supply of dry, saturated steam. Our technicians have all the necessary equipment and technical expertise to carry out and report on steam quality testing to the requirements of HTM2010, CFPP01-01, HTM2031 and EN285.

Typical steam quality variables tested are:

  • Non Condensable Gases
  • Dryness Fraction
  • Superheat

Steam Non Condensable Gases

The presence of air or other Non Condensable Gases contained in the steam supply to a sterilizer is likely to compromise the performance and efficacy of the sterilizing process.  Typically this will be indicated by Bowie-Dick test failures and inconsistent air detector performance.  

Steam Dryness

The dryness of steam for sterilization is of vital importance; excess moisture carried in the steam may result in wet load items and prevent even temperature distribution throughout the load.  Insufficient moisture is also detrimental to the sterilization process if for example, when the steam becomes superheated during expansion into the sterilizer chamber.
When measured in accordance with the HTM type steam dryness test, current standards require that the steam supply should have a dryness value of not less than 0.9.  Where metal loads are being processed, the steam dryness value should be at least 0.95.


Superheated steam is known to be unsuitable for moist heat sterilization and can result in sterilization failure, scorching or burning of textiles and paper, and deteriorate rubber items.
Current standards require that when tested in accordance with the HTM type superheat test, the superheat measured in the steam at atmospheric pressure should be less than 25DegC.

Laboratory Analysis

We are experienced at collecting water and condensate samples from sterilizers, washer disinfectors, endoscope re-processors and RO water systems for particulate and microbiological laboratory analysis.  All water and condensate samples are analysed at one of the UK’s leading microbiology test laboratories with comprehensive traceable reports included as standard.

To discuss your steam and water quality testing requirements further please contact us.

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