Standard Operating Procedure for the Steris Primus Unit in CEF-A

Request training and access by email to

Review approved Autoclave SOP with images.

Review UC Davis SafetyNet 26. Effective Use of Autoclaves.

Read the Manufacturer Primus Autoclave Operator Manual.

1.  HAZARD OVERVIEW (per UC Davis SafetyNet #26)

Autoclaves (steam sterilizers) are metal pressure vessels that are used for steam sterilization of media, instruments, and lab ware, and for decontamination of biological waste. Autoclaves function by pressurizing steam in an airtight chamber, which increases the steam temperature significantly. The superheated steam kills all microorganisms and degrades most macromolecules rapidly. Autoclaves are generally easy to use but they are ineffective and potentially very hazardous if operated incorrectly, especially if the door is opened too soon or too rapidly after a run is completed. Autoclave waste packaging, treatment, and handling are also subject to regulations which carry substantial penalties if waste is handled incorrectly. This SafetyNet provides a review of proper use of autoclaves to ensure that these devices are used safely, effectively, and in compliance with applicable regulations.


Users: Responsible for operating the autoclave in accordance with the parameters outlined in this SOP and per UCD SafetyNet #26 when the autoclave is being used to decontaminate or inactivate materials.  Users are responsible for selecting and verifying cycle parameters as appropriate for their materials and volume.  Users are also strongly encouraged to run monthly tests to ensure proper performance of the autoclave.  Users are responsible for handling research plants, soils, containers and other materials in accordance with their approved Biological Use Authorization (BUA), APHIS permit, and any other applicable requirements.  Users are responsible for maintaining records of autoclaved loads and biological indicator testing results.

Principal Investigator/Lab Supervisor:  Responsible for ensuring all laboratory personnel are appropriately trained in autoclave safety, general laboratory safety, and in the specific procedures as required by the BUA, APHIS permits and other applicable requirements.  PIs must ensure that BUAs and other safety protocols are current and comprehensive for all the laboratory, chemical and biological hazards relevant to the work.

CEF Facility Manager: Responsible for maintaining the autoclave in good working order and having autoclave tested annually by a qualified technician.  The facility staff are responsible for providing instruction on the operation of the specific autoclave unit in CEF-A (Steris Primus PSS11-B-MESD).

UC Davis Safety Services: Responsible for providing information on autoclave testing materials and training and guidance on effective decontamination methods to the campus community.


underlined materials are available at CEF

* materials marked with an asterisk must be provided by the user

  • long pants*
  • closed-toe closed-heel shoes*
  • lab coat
  • safety glasses or goggles
  • face shield*
  • long autoclave gloves
  • autoclaving pan
  • autoclavable bags
  • heat indicator strips
  • biological indicator (spores)*
  • string (for retrieving biological indictor)
  • disposable gloves*
  • tongs or other tool for biological indicator retrieval*


4.1.  Reserve time slot via the CEF PPMS software.

4.2.  Ensure proper PPE: long pants, closed-toe closed-heel shoes, lab coat, safety glasses or goggles, disposable gloves and long heat-resistant autoclave gloves.

4.3.  Collect waste plant and soil material in an autoclavable bag and transport to the autoclave area in a secondary containment vessel to prevent spills.  Do not overload autoclave bags.  Waste should be no deeper than 8 inches or 20 cm.  Steam will not penetrate large loads sufficiently to provide decontamination.  Do not tightly cinch or seal bags.  Steam must be allowed to penetrate load.

4.4. If using a biological indicator, tie a string to ampule and bury it in the middle of the load, leaving the string accessible for retrieval after autoclaving.

4.5.  Verify that the autoclave is ready for loading.  Touch the screen to confirm that the autoclave is IDLE.

4.6.  Slide down the door and place autoclave bag(s) inside the autoclave pan.  Do not place bags directly on metal grate.  Ensure to leave at least 2 inches or 5 cm of space on all sides around the autoclave bags to allow steam to penetrate the bags.

4.7. Slide up the door to close.

4.8.  Log in to the autoclave system by selecting your assigned UserID (OPR1, OPR2, etc) and enter password (4-digit code).  If you forgot the password, please contact CEF staff for assistance at

4.9. Jacket conditioning may start automatically if this is the first run of the day.  Jacket conditioning warms the walls of the autoclave in preparation for operation.  This phase can take 5 – 10 minutes.

4.10.  Select the appropriate cycle.  Most plant material can be autoclaved using WASTE_120_min.  This provides for 120 minutes (2 hours) of sterilization at 121 C and 14 – 15 psi. Total autoclave operation time for this cycle is about 3 hours.

Additional cycles include

  • WASTE_30_min
  • WASTE_60_min
  • WASTE _240_min

IMPORTANT:  Users are required to verify the proper cycle for the material and volume of load.  Users should verify effective decontamination through use of biological indicators (spore ampules buried in the load and incubated afterwards).

4.11.  Press START at bottom menu.  Confirm Start for the cycle selected.  During jacket conditioning, the START key is not shown.  Wait until jacket conditioning is complete.

4.12.  Enter information on autoclave load and user in the paper autoclave log.

4.13.  Monitor autoclave operation.  The autoclave should automatically transition between the phases of operation.  See specifications for each phase at end of document.

  • Start
  • Purge
  • Pre-pulsing
  • Heatup
  • Sterilizing
  • Exhaust
  • Equalize
  • End

4.14.  At cycle end, verify the screen reads CYCLE COMPLETE in upper right.

4.15.  Ensure proper PPE: long pants, closed-toe closed-heel shoes, lab coat, safety glasses or goggles, disposal gloves and long heat-resistant autoclave gloves.

4.16.  Stand away from the door and open door slowly by sliding down.  Use caution when opening door, as a small amount of steam may be released.

4.17.  Wait at least 10 minutes with door open to cool.  Remove bag(s) and place in a secondary container.  Verify that heat indicator tape or strips have confirmed operation. 

4.18.  Log out of the autoclave and complete the autoclave log with any notes about the run.

4.19.  Retrieve biological indictors from cooled load, if applicable, ensuring proper PPE: long pants, closed-toe closed-heel shoes, lab coat, safety glasses or goggles, and disposable gloves.  Please do not use autoclave gloves to retrieve spore ampules.  Retrieve the ampule using the string attached when preparing the load and with the assistance of tongs if needed.

4.20.  In your lab, incubate the biological indicator as instructed for the specific product, as applicable.  Repeat autoclave cycles for any unverified or failed loads.

4.21.  Once effective decontamination has been confirmed, dispose of autoclave bag(s) directly in large outside waste dumpsters to the north of the rear loading dock.  Do not put autoclaved materials in the inside plastic bins.

Please contact CEF staff if autoclave fails to operate correctly,

and with any questions or concerns.      

office: (530) 752-1906

In case of emergency, call 911.