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batch control EtO

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gke EtO BATCH MONITORING SYSTEM

The ethylene oxide monitoring indicator system has been developed to check each batch of the ethylene oxide sterilisation cycle. 
The indicator system may be used for pure ethylene oxide under low pressure conditions and also for ethylene oxide CO2 or inert gas mixtures under pressure.

EtO/l (mg)  Pressure (bar) CO2(%) CO2(%)  Time (min) 
500  1.7 85 15 90
600 5.5 94 6 60
250 1.7 94 6 180
1200 5.5 85 85 30
600 0.2 0 100 60
         

During the sterilisation process it is absolutely necessary to monitor the relative humidity, which should be above 50% and never drop below 30%.

The attached process challenge device (PCD) which has a connected Teflon tube of 1.5m length simulates worst case penetration conditions. 
If a sterilisation cycle without pressure differences is used the penetration of ethylene oxide in the PCD may be too difficult.  If so remove the Teflon tubing from the metal holder or place the indicator in sever sterilisation bags to simulate worse case penetration conditions.

Sterilisation programs are not standardised.  Therefore a validation with b. subtilis bio-indicators is required before the chemical indicator can be used for routine sterilisation monitoring.

gke produces Steri-Record® bio-indicators b.subtilis 106 for ethylene oxide sterilisation processes on paper strips or self contained Bio-Pus indicators.

Directions for Use

  1. As described above, select the right package depending on your sterilisation cycle and validate the process with bio-indicators.  Always use the same sterilisation cycle and the same chemical indicator packing procedure during each validation and routine monitoring run.

  2. Insert the indicator strip in sterilisaton bags or the enclosed PCD.  Fold the indicator strip in the middle and place it in the test device with an opening towards the tubing inlet.  Make sure that the washer is in perfect condition and close the cap.

  3. Place test system including indicator between sterilisation goods and place one unprotected indicator as a reference in the chamber close to the bottom and near the door.  Start the sterilisation program.

  4. After the ethylene oxide extraction stage remove the indicator from the test system and check the result against the reference indicator or reference chart.

  5. All four indicator bars on the strip must change colour from blue to green.  Use the unprotected indicator strip as a reference.

  6. Release the sterilisation batch depending on colour result and attach the indicator strip (which is self adheseive) to the documentation page. 

Documentation Information

Important Considerations

gke Steri Record
Batch Monitoring Indicator System