Double Door Autoclave Operation, Cleaning and Calibration procedure

1.0 OBJECTIVE

To describe a procedure for Operation, Cleaning and Calibration of Double Door Autoclave Make: Osworld 

2.0 SCOPE

This procedure is applicable to Operation, Cleaning and Calibration of Double Door Autoclave in Microbiology Lab.

3.0 RESPONSIBILITY

3.1 Microbiologist /Officer is responsible for the execution. 

3.2 HOD or designee is responsible for review, effective implementation and compliance to the Operation, Cleaning and Calibration of Double Door Autoclave for execution.        

4.0 PROCEDURE 

4.1 OPERATION OF AUTOCLAVE

4.1.1 Check the water level before starting the autoclave. If the level is down, then fill it up to the level marked.

4.1.2 Switch on the mains to supply the power, red light indicator will glow and followed by the toggle switch located in the control panel to activate the heat generator, orange light will glow. The digital temperature controller led will glow and indicates the present actual temperature in the autoclave i.e. ambient temperature.

4.1.3 Set the multi port-operating valve in slow exhaust position, allow the steam to build in the outer jacket till the pressure reaches 14-17 psi.

4.1.4 Then press the printer P button on digital temperature controller and then Press the start button, it will display the set parameters of autoclave i.e. temperature and holding time of sterilization.

4.1.5 Open the door at loading side and load the necessary items to be sterilized.

4.1.6 Place the autoclave indicator strips at different places in the autoclave for each cycle to indicate the proper sterilization by color differentiation of the strip.

4.1.7 Close the door using the radial locking handles clockwise till it is tight.

4.1.8 Turn the multi port-operating valve to ‘Ster’ position.

4.1.9 Then the temperature and pressure increases slowly, compound gauge shows 15-17 psi and subsequently the dial thermometer shows a rise in temperature to121 - 123°C.

4.1.10 When it stabilizes at set temperature and pressure, the timing for sterilization begins. Once the temperature and pressure reaches set parameters timer automatically starts sterilization mode.

4.1.11 After the stipulated sterilization time is completed controller alarms for exhaust, then set the multi port-operating valve in ‘Slow exhaust’, for liquids in bottles and  in Fast exhaust’ for all other loads.

4.1.12 In case of vacuum drying turn the multi port-operating valve in ‘Vacuum dry Position’.

4.1.13 Once the temperature in the sterilizer drops to 60°C or the pressure drops to 0 psi, Switch off the system, unload the items by opening the door at unloading side of autoclave.

4.1.14 After completion of the sterilization cycle, Connect the printer to printer interface of the autoclave controller for printer report, it will provides date, time, temperature and pressure etc details while on sterilization condition.

4.1.15 A safety valve is provided, in case excess pressure builds up it is released through the safety valves.

4.1.16 Enter the details like Particulars of the loaded material and sterilization time in the double door autoclave log book as per Attachment#1 format QEO015/F01.

4.1.17 Indicate the load no as A-XXX, where ‘A’- Autoclave no. and ‘XXX’ - serial number in sequence. Ex; 2-001 for Double door autoclave load/cycle number one.

4.2 CLEANING OF AUTOCLAVE

4.2.1 Clean the autoclave after each cycle with purified water.

4.2.2 The inner chamber shall be cleaned with 2.5% savlon or 2.5% dettol every day at the end of each cycle.

6.2.3 Keep the autoclave in closed condition while not in use.

4.2.4 Clean the drain line by pouring hot solution of tri sodium phosphate (3.0% in purified water) through the drain hole in the chamber for cleaning of grease, sticky substances to avoid clogging. This should be done for every fifteen days.

4.2.5 Prepare the cleaning solutions as per current version of SOP. 

4.2.6 Enter the details of cleaning in to the autoclave cleaning record as per    attachment #2

4.3 CALIBRATION

Validation by thermal probes: 

The validation of autoclave is carried out by following methods, Heat Distribution studies and Heat Penetration studies and by using biological indicator strips/ampoules of Bacillus stearothermophilus.

4.3.1 Heat Distribution test.

4.3.1.1 Place calibrated thermal probes in different locations within the autoclave as per the attachment # 3.

4.3.1.2 Place the probes in such a manner that the tip does not have any contact with   the body of sterilizer.

4.3.1.3 Run the autoclave as per the point no 6.1

4.3.1.4 Record the temperature at the intervals of each minute all through the cycle

4.3.1.5 Run the three consecutive cycles

4.3.1.6 Place the biological indicator at or near to the probes placed.

4.3.1.7 Place the Bowie Dick test pack at the center of the chamber.

4.3.2 Heat Penetration test

4.3.2.1 Place the probes in such a manner that the tip does not have any contact with the body of sterilizer.

4.3.2.2 Run the autoclave as per the point no 6.1

4.3.2.3 Record the temperature at the intervals of each minute all through the cycle.

4.3.2.4 Run the three consecutive cycles each for minimum and maximum loads.

4.3.2.5 Place the biological indicator at or near to the probes placed.             

4.3.3 Method of analysis for biological indicator

4.3.3.1 Place the ampoule / strip of Bacillus stearothermophilus spores in a empty test tube, and numbered it. 

4.3.3.2 Take the tubes to respective area and place them in autoclave at or near to the   probes placed.

4.3.3.3 After completion of sterilization cycle remove the tubes from the autoclave and carry out the analysis.

4.3.3.4 In case of strip, aseptically transfer the Bacillus stearothermophilus strip from each tube into separate tube of sterile Soyabean casein digest medium.  Mark the tubes appropriately.

4.3.3.5 Aseptically transfer a non-autoclaved Bacillus stearothermophilus strip into a tube sterile SCDM to serve as positive control.

4.3.3.6 Mark one tube of sterile Soyabean casein digest medium as negative control.

4.3.3.7 Incubate all the tubes at 55-60°C for seven days and observe them every day for any visual evidence of growth.

4.3.3.8 In case of ampoule for Bacillus stearothermophilus, incubate the ampoules as such at 55- 60°C for at least 48 hours.

4.3.3.9 Keep one un-autoclaved ampoule along with the tested ampoules to serve as positive control.

4.3.3.10 Record the results in attachment # 4

4.3.3.11 If there is no evidence of growth in any of the tubes except positive control or if the color of the ampoules remains purple or turns reddish brown, the results are valid.

4.3.3.12 If evidence of growth in any of the tubes except positive control tube or ampoule (color change to yellow) the results are invalid.  Repeat the test procedure using fresh Bacillus stearothermophilus strips / ampoules.

4.3.4 ACCEPTANCE CRITERIA

4.3.4.1 The entire chamber area should show the set temperature uniformity and steam stability during Heat distribution test and heat penetration studies. Achieving a temperature of 121° C with saturated steam at the approx.  1.2 Kg/cm2 (bar) pressure.

4.3.4.2 The coolest point within the chamber area should be determined in the heat distribution test.

4.3.4.3 The coolest point within a specified load and configuration should be determined during the heat penetration test.

4.3.4.4 All exposed Biological indicators should show negative result in the entire cycles.

4.3.4.5 A Range of + 3°C of the mean chamber temperature is acceptable.