Testing to determine if the sterilizer is operating to set conditions of time, temperature, pressure, air removal, moisture conditioning and sterilant exposure.
The 3M recommended best practice is to run daily a steam penetration test, in pre-vacuum steam sterilizers at the following times:
- Once daily, at the same time every day, before first processed load;
If the penetration test shows no problem, you can begin your daily sterilization routine by continuing to monitor the physical monitors on your sterilizers, which is the other type of Equipment Control Monitoring.
Depending on your quality system it might be necessary to perform an Air Leakage Test, as well.
Before running a penetration test, you should run your sterilizer on an empty cycle, even if it was never turned off. This reduces the chance for an invalid test. When running the test, the penetration test should be the only item in the load. The test pack or device should be placed horizontally in the front, bottom section of the sterilizer rack, in the middle of the steam sterilizer, always on the same position.
Physical monitors are the gauges on the sterilizer that record time, temperature and pressure so you can identify an equipment malfunction before it becomes a problem. Incorrect gauge readings, or readings that vary from set conditions, indicate a malfunction and you should consider the load non-sterile. The sterilizer should be taken out of service until you make adjustments or the problem is corrected.
Steam penetration tests are the original Bowie & Dick test pack, specified in the ISO 11140-3 and alternative penetration tests. The alternative tests have to fulfil the requirements in the ISO 11140-4. Most alternative tests are either equipped with chemical indicators or with parametric indicators (UK, English). In Europe there is a tendency to go to physical indicators, like the ETS. All tests have there pro’s and con’s. For example, chemical indicators are easy to use, but if a problem is indicated, it is difficult to conclude what the problem might be. With a parametric penetration test, data can be made available for trouble shooting.
Reminder: If your quality system is based on European norms, it might be necessary to perform an Air Leakage Test (ALT) periodically or even daily.
Bowie, Kelsey and Thompson, the Bowie and Dick autoclave tape test, the Lancet, Vol. 16, page 586-587, March 16, 1963
J.P.C.M. van Doornmalen, J. Dankert, A validation survey of 197 hospital steam sterilizers in The Netherlands in 2001 and 2002, Journal of Hospital Infection, 59, 126–130, 2005
J.P.C.M van Doornmalen, K. Kopinga, Review of surface steam sterilization for validation purposes. American Journal of Infection Control, 36, 86-92, 2008
ISO 11140 Sterilization of health care products - Chemical indicators
ISO 17665 Sterilization of health care products - Moist heat
EN 285 Sterilization - Steam Sterilizers - Large Sterilizers