How to Validate an Autoclave: Performance Qualification (PQ)

Written by:Amit Gupta

An autoclave undergoes qualification testing in order to validate and verify that it’s performing consistently and properly. In previous posts, we outlined the first two qualification tests known asInstallation Qualification(IQ) andOperation Qualification(OQ). In this post we will review Performance Qualification (PQ) as a final critical step invalidating your autoclave.

What is Performance Qualification (PQ)?

PQ demonstrates that the autoclave not only runs the required cycles, but provides the required result: sterility. The PQ process involves testing the loads that must be successfully sterilized in the autoclave. The prerequisites for PQ are successful IQ and OQ.

Performance Qualification (PQ) –A process which obtains and documents evidence that the autoclave, as installed and operated in accordance with operational procedures, consistently performs in accordance with predetermined criteria and thereby meets its specification.[ISO TS 11139:2006, definition 2.30]

Sample Test Protocol

PQ由每个定义的负载至少由三个重复测试组成。测试的关键方面是验证每个载荷中的无菌性。每种负载类型都会有自己的挑战，因此重要的是，每个负载类型都必须用以下信息指定：对物体的数量和类型进行消毒，所使用的无菌屏障材料，在某些情况下，在高压灭菌器中对物体进行灭菌的方向。

Here is a sample PQ test protocol:

1. Objective

The Objective is to prove sterilization of the specified load. The sterility assurance level may derive from a standard, from a client SOP or specification, or from a manufacturer’s specification. Specific citations to any of these should be made in this section.

2. Procedure or Setup

The Procedure or Setup explains how to setup and execute the test. The following specifications should be noted here:

The type of cycle (dynamic air removal, gravity, liquid, air-overpressure during cooling, air overpressure support, water cascade, etc.) including all critical parameters
Any equipment needed for the test
The number and location of each item in the load
If a mixed load is to be run, the number of each item and the items’ locations should be specified.
Locations of the indicators and datalogger probes – these should be placed in “worst-case” locations in the load to provide assurance that the entire load is sterilized
Sterile barrier materials or vessel covers (like aluminum foil for flasks), as well as their application to the items closed by them
A step-by-step listing of how to carry out the test

3. Acceptance Criteria

The Acceptance Criteria section lists the required result or range of results. Examples of acceptance criteria for Performance Qualification involve sterility and temperature. For example, if the “acceptable criteria” for the temperature range within the chamber during sterilization is -0/+3°C relative to the actual set point, then the chamber temperature at all measured points must be within that range for a successful outcome to be recorded.

批判“接受标准”的另一个例子是不育，这是通过使用生物学指标（BIS）证明的。显而易见的结果是，BI上不应有幸存的孢子。如果有幸存者，则应进行BIS的检查，以确保BIS的抗性（即D值）不大于原始周期开发中使用的BI。

4.结果记录

The Result Record is where all of the test data is recorded. At least three iterations are typically run for process tests. Any failure to comply with the acceptance criteria makes an “iteration” a failed test. The required number of iterations must be run successively with successful outcomes for the test to be considered a pass. The record must include:

Sterilizer cycle tape or electronic record
Biological (and chemical, if used) indicator results
Datalogger results and their compliance with the Acceptance Criteria
分析累积致死性（FO）的数据记录（热电偶）记录，并符合曝光阶段允许的负载温度范围

5. Verification

After the testing is done, the results are typically reviewed for compliance with the acceptance criteria. The review is finalized in this section with signatures from the person who ran the test and, preferably, with countersignature of a second person or manager.

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Sterility Testing & Record Keeping

灭菌周期应依次运行，负载设置应遵循测试的过程或设置部分。指示器和数据记录器探针应按指定放置。无菌屏障或封闭材料应按照指定应用。如果要重复使用样品负载，则应允许它们冷却至周期之间的指定温度（最佳室温），以提供用于消毒器的现实世界热载荷，并为指示器提供现实世界中的暴露。

In all tests, record keeping is essential to the integrity of the test. Records may include cycle tape printout from the sterilizer, data logger data files, photos, sketched diagrams, etc. These must be attached or provided with the report, with each identified by the section of the PQ protocol to which it applies. Any electronic data records should be provided in a non-volatile form with the final report, i.e., as a CDROM or DVDROM, or via cloud storage.

A more extensive list of the required records is listed here:

谁进行了测试，结果的验证以及具有首字母和签名的批准的目录。
A listing of reference or other test equipment, manufacturer, model, serial number, and calibration due date, if applicable.
A listing of biological indicators and chemical indicators (if used), including manufacturer, model number, lot number, D-value, and nominal population.
- 如果使用培养液,复苏研究应当堂e to ascertain the actual recoverable population of the indicators; also, a growth promotion study shall be done to ensure that the item upon which the inoculum is deposited does not have a negative effect on outgrowth of the indicator organism
A calibration record for test equipment (e.g. thermocouples) if done at the work-site, both before and after a series of tests and/or after the entire test protocol is performed.

A well-executed PQ will enable you to demonstrate and document that the autoclave can execute the desired processes and provide the sterility assurance level that is required for your application. PQ is generally the final step in qualification. This testing creates an unassailable baseline level of proof of the autoclave’s ability to do the specified job, and is the basis for requalification at periodic intervals.

If you have additional validation questions or any questions related to autoclaves in general, pleasecontact usfor more information.

(Co-written by Jonathan A. Wilder, Ph.D.,Stericertdiv. of H & W Technology)

Amit Gupta

Amit has over 15 years of experience engineering multi-disciplinary systems and brings his passion for engineering, innovation and quality to his work every day. Prior to joining Consolidated Sterilizer Systems in 2007, Amit worked on robotics at the Charles Stark Draper Laboratories. Additionally, he designed medical devices and scientific equipment such as novel catheters and DNA hybridization chambers for microarrays. A true engineer at heart, Amit enjoys breaking things just to figure out how to fix them; his love of tinkering even extends to assembling IKEA furniture. He graduated from the University of Pennsylvania with a B.S. in Mechanical Engineering and from MIT with an M.S. in Mechanical Engineering.