How To Validate an Autoclave: Installation Qualification (IQ)
There is an array of qualification tests that can be conducted to validate an autoclave. Many laboratories validate autoclaves by simply using biological indicators (BI’s). For some labs, however, a simple validation with BI’s is not enough and a more elaborate validation process must be followed.
These labs typically require installation, operation, and performance qualifications (IQ/OQ/PQ) to help comply with the current USA and International Standard for steam sterilization as set forth in ISO 17665. In this article, we will examine Installation Qualification and what it does for you.
What is Installation Qualification (IQ)?
Installation Qualification (IQ) provides documentary evidence that the equipment has been built and installed to specification, and that all supporting services (i.e., utilities such as electricity, water, and steam) are available and connected properly. The IQ process methodically documents all aspects of the installation, the machine components, and any testing equipment used to provide a complete, closed-loop assessment. In addition, IQ includes NIST traceable calibration verification of the unit’s critical components. More on this later.
IQ begins before you issue the purchase order for the autoclave. Completing a successful IQ is the result of careful planning and there should be no surprises when the unit arrives at your facility. Naturally, what you ordered and what you receive should match.
IQ is typically carried out concurrently with installation or soon after installation at the user’s facility. The IQ is performed by following a specific IQ protocol tailored for each piece of equipment.
Installation has requirements that are unique to each machine, or at least should be treated that way. As part of IQ, these requirements must be verified. They include:
- Electrical: voltages, current, fusing, correct number of phases, and three-phase configuration
- Compressed air: pressure (static AND dynamic), flow
- Water: pressure (static AND dynamic), flow, temperature(s), purity(ies), dissolved gas content
- Steam: pressure, purity, pipe insulation, pipe size and peak flow rate
- Drain: capacity, temperature tolerance
- Dimensions: including space to allow service
- Free-standing or through-wall mounting
- Biosafety barrier
- Seismic anchoring
- Leveling: for sterilizer performance and to align with delivery cart for removable load carriages
An IQ should list the requirements and provide documentation of the presence and adequacy of each utility and feature listed above (if so furnished).
Documentation for the ongoing operation and maintenance shall be confirmed. These documents include:
- Operator and service manuals
- Electrical schematics
- Piping and instrumentation diagrams (P&ID’s)
- Purchased part documentation
- A list of spare parts
- Pressure vessel certifications (chamber and boiler)
An IQ should also systematically catalog all of the items on the bill of materials and verify that the machine has been built to drawing. Listing and verification of the presence of each sensor, transducer, valve, pump, and gauge shown in the P&ID or bill of materials should be part of this portion of the IQ. The process compatibility should be verified for sensors, transducers, valves, pump(s), and gauges exposed to the process. The accuracy of transducers and sensors used to control or record critical process parameters should be verified to meet the criteria provided in the relevant standards.
The final portion of an IQ is the most interesting one, as power is finally applied to the unit. Testing in this portion of the IQ includes calibration and, for systems with motors, ensuring that the motors turn in the right direction.
Calibration requires standards that are traceable to the standards maintained by the United States National Institute of Standards and Technology (NIST). In other countries, traceability is to be to that country’s national equivalent of NIST.
- Transducers and Sensors – For autoclaves, this means that a pressure standard and a temperature standard should be available, as well as a means of providing stable pressure for calibrating the pressure transducer(s) and a dry block or oil bath for calibrating the temperature transducers. Optimally, a calibration standard should be five times as accurate as the device being calibrated needs to be. For a ±0.5°C accuracy on the sterilizer, the standard should have an accuracy of ±0.1°C. Details of the calibration depend upon the sterilizer’s controls system and how it handles calibrations. Generally, at least a three-point calibration is required, with more points providing a better indication of the linearity of the system. The golden rule of calibration is, “If you do it fast, you get to do it twice.” So waiting for a stable value is key in a successful calibration.
- Time – Another aspect of calibration is that of the internal clock of the sterilizer. The standards related to steam sterilizers generally have accuracy requirements for the process control clock(s) in the controller. Testing is straightforward, since NIST has a dial-in phone number (303-499-7111) that tells you the national standard time on a one-minute interval, providing you with ±1 second accuracy. This level of accuracy is adequate for any laboratory autoclave. Measurements at either end of a 24-hour period would be acceptable to any audit.
A thorough IQ will enable you to have confidence in your autoclave, and more importantly, documented proof of its ability to carry out the task at hand, not just because the manufacturer tells you so, but also because it has been demonstrated in place. IQ is a critical part of the process for fully commissioning an autoclave and putting it into its appointed use.
If you have additional qualification questions or any questions related to autoclaves in general, please contact us for more information. Also, stay tuned for future posts on How to Validate an Autoclave.
(Written by: Jonathan A. Wilder, Ph.D., Stericert div. of H & W Technology)
How to Validate an Autoclave
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