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This article was originally published in 2016, and has been updated to meet standards of 2018 as well as include the new V-PRO® maX 2 Low Temperature Sterilization System and the Celerity® 20 HP Biological Indicator.

ANSI/AAMI ST58 Chemical Sterilization and High-Level Disinfection in Health Care Facilities is an essential reference document for healthcare facilities in the US conducting chemical high level disinfection or sterilization during device processing. This guide provides a quick reference for suitable quality assurance for use of the V-PRO® Low Temperature Sterilization System that is consistent with ANSI/AAMI ST58.

The V-PRO Sterilizer is intended for use in the terminal sterilization of cleaned, rinsed, and dried metal and nonmetal medical devices. The preprogrammed sterilization cycles operate at low pressure and temperature, suitable for processing medical devices without leaving toxic residues.

Quality Assurance Methods

ANSI/AAMI ST58 recommends several quality assurance methods to help ensure effective chemical sterilization of medical devices. These are similar to the manner in which quality assurance requirements for steam sterilization are recommended within ANSI/AAMI ST79 Comprehensive guide to steam sterilization and sterility assurance in health care facilities.

The recommendations for chemical sterilization in ST58 include:

  1. Monitoring Every Load –This routine testing includes the use of physical monitors to verify an effective chemical sterilization process has been conducted for each load. Physical monitors are defined by the system manufacturer and may include displays or printouts of cycle parameters (temperature, pressure, exposure time etc.), in some cases biological indicators (BIs) and chemical monitoring devices or chemical indicators (CIs). This also includes correct use and monitoring of the device by the processing staff and/or the staff preparing instrumentation for patient use.
  2. Routine Testing – This testing should be conducted daily, preferably every cycle, as recommended by the sterilization process manufacturer, and verifies that the process is operating properly. It includes defined diagnostic testing.
  3. Qualification Testing – This includes running consecutive diagnostic, BI and CI tests to verify the equipment is operating properly after a major event, such as: installation, major repair, relocation, or in the event of a sterilization failure.
  4. Periodic Product/Load Quality Assurance Testing – This testing is performed to verify that the expected results are achieved when following the chemical sterilization process manufacturer’s IFU as well as the instrument manufacturer IFU. It includes testing for sterilant exposure with typically used devices and by using BIs and CIs.

Most facilities are familiar with the first three quality assurance methods above. These monitoring methods help to provide confidence that the sterilization process is working as intended. However, many facilities are less familiar with the recommendation for periodic product and load quality assurance testing. While AAMI ST58 recognizes that the sterilization process manufacturer and the device manufacturer are in the best position to make recommendations for sterilization parameters, it is also recommended that end users periodically test and verify processing of instrument sets/loads given their local utilities and load configurations. This testing will be specific to each facility depending on what they consider a typical load.

Quality Assurance Monitoring with the V-PRO® Sterilizers

The following Table provides a guide to recommended quality assurance monitoring with the V-PRO® series Low Temperature Sterilization Systems, with consideration of AAMI/ANSI ST58. These include the V-PRO®1, V-PRO®1 Plus, V-PRO®maX and maX 2, as well as the V-PRO®60:

Monitoring Each
Pack and Load
Routine Sterilizer Testing
Quality Testing
after Installation
or Major Repair
Periodic Product/Load Quality Assurance Testing
To verify an efficient sterilization process has been conducted for each pack within each load Daily testing to verify that the sterilizer is operating properly Verify that the sterilizer is operating properly after a major event: Installation, Major Repair, Relocation or Sterilization Failure Verify defined loads and loading methods specific to a facility
Physical Monitoring
(inspection of the cycle printout)1
Physical Monitoring
(inspection of the cycle printout)1
Physical Monitoring
(inspection of the cycle printout)1
Physical Monitoring
(inspection of the cycle printout)1
Packaged devices:
Internal/External CI
Packaged devices:
Internal/External CI
LEAK TEST Cycle Position CIs and BIs within the load/packaging (representing typical facility practices) at worst case locations.
Daily (preferably, every cycle) with a BI (may also include a CI). Preference to include in the first load of the day and on the shortest cycle Three cycles (consecutive) with a Challenge Pack (containing a BI and CI). Testing in an empty chamber, on the shortest cycle.
Monthly LEAK TEST Cycle, preferably first working day, first shift in the morning.

Refer to ANSI/AAMI ST58, ANSI/AAMI ST79, the Operator Manual for the specific V-PRO® series Low Temperature Sterilization System, and the instructions for use for VERIFY HPU Chemical Indicator, VERIFY V24 Self-Contained Biological Indicator or the Celerity® 20 HP Biological Indicator for more information.

For more help with the quality assurance of your V-PRO® Low Temperature Sterilization system please reach out to a STERIS representative, visit or call 1-800-548-4873


CI: VERIFY® HPU Chemical Indicator; BI: VERIFY® V24 Self-Contained Biological Indicator or the Celerity® 20 HP Biological Indicator
1. V-PRO® Low Temperature Sterilizers have an integrated independent monitoring system that confirms the essential process variables for sterilization; this can also be verified by inspection of the cycle printout.