Sunday, August 2, 2009


1. Objective:

To lay down standard operating procedure for Dry heat sterilizer

2. Scope:

This procedure provides a detailed method of operation and handling of the Dry heat sterilizer.

3. Responsibility:

¯ Operator.

¯ Senior Chemist.

¯ Head - Production.

4. Procedure:

4.1. Make sure that Line clearance is duly checked and signed by QA Personal as per SOP No:P/P/051

4.2. Wash the SS Box and clean the chamber of the dry heat sterilizer with DM water.

4.3. Run the sterilizer for half an hour by keeping the damper open after the first cleaning, to takeout all settled dust from its.

4.4. Turn off the sterilizer to clean the chamber by DM water with Non-fiber releasing cloth.

4.5. Place the load to be sterilized into the SS Box and put the SS Box back into the chamber of the dry heat sterilizer.

4.6. Close the pressure lock door, by pulling up the quick throw handle and turn the handle clockwise till the door is tight.

4.7. Switch on the main supply.

4.8. Set the temperature on the control panel depending upon the load to be sterilized.

For example: 2000C for Ampoules/Vials & 1100C for Wads.

4.9. Switch on the Heater 1, Heater 2, Heater 3, Damper and HEPA Filter.

4.10. The temperature will gradually rise and will be indicated by the temperature indicator.

4.11. Switch off the Damper and HEPA filter after the temperature reaches the 1500C, to remove water vapour from the chamber and filter the air which is coming from atmosphere to the chamber respectively.

4.12. Switch off anyone one of the heater after the temperature attains 2000C.

4.13. Maintain the same condition for validated time which is depending upon the load to be sterilized.

For example: 2 Hrs for Ampoules/Vials and 3 Hrs for Wads.

4.14. After the sterilization cycle is completed, Switch off the main supply.

4.15. Prior to unloading the sterilized load on the sterile side, Switch on HEPA filter & open the damper to reduce the temperature to 1000C and then switch off dryer. Make sure that the sterilized load has been cooled to room temperature and the door of Non-sterile area is closed.


ronak said...

what would about sensors which are working in DHS System & what is the timing frequency to validate DHS? Please give information for AUTOCLAVE also

saratpriya said...

It will vary from company to company, but preferabbly every six months would be sufficient. We need to challenge initially all load patterns i.e. empty dryer for distribution study and different load patterns for heat penetration studies.
After that for every six months one distribution and one load pattern can be justified.

Same way for autoclave also i.e. distribution and penetration (Bowie-Dick test) studies. Apart from the above need to do condensable gases test and steam dryness test.

For both DHS and autoclaves, temperature probes need to be calibrated every six months/one year. Also, pre and post calibration of probes should be performed before and after qualification.