In addition to the discussion of BD - regarding the question whether this test is still necessary in modern, well programmed sterilisers - I would like to pose the following question:

Is it really necessary to perform a yearly validation of your sterilisers if you have the opportunity to gain independent data such as temperature and pressure by a validated probe in the steriliser? (e.g. EBRO)

I know that a datalogger is not a substitute for validation - but is the timespan of a yearly validation still a necessity? If we have access to reliable data which we can obtain every week, every month, or anytime we want, why not prolongue this validation to 2 or 3 years if we are supported by other reliable and independent data?

I mean, what is best: do a rigourous validation every year without any information in between, or have access to information that is obtained on a regularly basis and perform the validation every 2 or 3 years?

Ludwig Van de Voorde
CSA - 03.760.2962
AZ Maria Middelares Sint-Niklaas

Ludwig !

Validation is a planned and documented process carried out during operational circumstances to verify a repeatable and continuous production of quality controlled product.
The Steriliser has become a sophisticated machine and not a simple pressure cooker raising temperature under steam pressure, the medical device ,that is the steriliser and the manufactured product the implant or surgical instrument need to be routinely monitored and that word again validated. Validation is not just a measurement of time, temperature and air removal by a surrogate measuring device but a measurement of all the control devices that are in a sequenced application utilised to achieve assured sterilisation.
So in conclusion Validation is a complete process were predetermined parameters are measured and verified, This include the performance of the vacuum system, quality of steam,engineering components and all the safety devices that protect the user and the medical device from a volatile process.
It is worth remembering the quote from Cecil Clothier on the Plymouth disaster.
"To many people believe that sterilization of fluids is easily achieved with simple plant operated by men of little skill under a minimum of supervision - PUBLIC SAFETY in this as in many other technological fields depends on ultimately on untiring vigilance"

Ludwig

I know that Hugh O'Connor has already answered your question but the use of routine testing is also an essential part of the parametric release of goods from each individual cycle. The initla validation of the machine will set the "fingerprint" which must be followed - within acceptable limits - on each subsequent cycle. Routine testing will confirm that the instrumentation, control system and independent monitoring continue to provide accurate, believable data for the product release decision to be made. The use of external devices is complementary to this but routine testing must use techniques similar to the initial validation to demonstrate the provision of valid data

Best wishes - Peter Hooper

next question: why is validation related to time and not - which is more obvious I think - to the amount of cycli ran by an autoclave?

Dear Ludwig,

I think the reading of EN 554 "Validation and routine control of sterilization by moist heat" can make things more clear.

Clause 5.6. Performance requalification says:
"5.6.1. Performance requalification shall be performed at defined intervals and whenever a change is made to a sterilizer load which is not within the limits specified in the performance qualification report.
5.6.2. The responsability for determing the necessity and the extent of repeating parts of performance qualification shall be assigned to a designated person trained in this specialism (see 5.1.2.)"

"Annex A (informative) of EN 554 Guidance on the application of EN 554 explains in A.3.6. Performance requalification:
Performance requalification may need to be performed after recommissioning or at an intermediate period such as a change of product, product packaging, or loading pattern, or when the data for the sterilizer load are not within specified limits. However in the latter case, it may be necessary to first repeat some of the commissioning tests and then, if the new data differ in an unacceptable way to those obtained during validation, a repeat of validation is required. Routine performance requalification should, typically, be performed annually and be a repeat of a performance qualification study for at least one of the sterilizer loads sterilized routinely and for which performance qualification records are available.
To facilitate comparison of performance qualification and performance requalification data, it is normal for the same report format to be used."

The period of one year shall undoubtedly be inspired by safety reasons.

Kind regards,
Wim Renders

Ludwig,

Your question regarding the interest of using a B&D daily and to keep the annual validation for the sterilisers is very interesting for many reasons. As you said, sterilisers are now more and more well programmed with a lot of new technologies and monitoring.
In the most european countries, the autoclaves are validated once a year + each time after maintenance interventions or after a change of product, packaging etc... This is important to do it annualy to have a "reference" for each cycle with each typical load used in the CSSD.
Regarding the B&D test every morning we should actually speak in terms of "steam penetration test", that allows the CSSD manager to do it with different methods than the classic B&D sheet. There is now some electronic monitoring probes used for this but also for each cycle. These kind of systems are interesting because it is totally independant from the autoclave.
This is also a way to have a load validation system for each load, in each steriliser, based on physical measurement. Used in routine it can help to check daily if your autoclave is still under the last anual validation parameters and so, prevent any maintenance from the biomedical department or the manufacturer of the machines itself.
It exist an international standard which is from my point of view the only one to speak clearly about the load validation in routine:
The EN / ISO 14937 from year 2000:

Sterilization of health care products - General requirements for characterization of a sterilizing agent and the development, validation and routine control of a sterilization process for medical devices
Stérilisation des produits de santé - Exigences générales pour la caractérisation d'un agent stérilisant et pour le développement, la validation et la vérification de routine d'un processus de stérilisation pour dispositifs médicaux

10 Routine monitoring and control
10.1 The purpose of routine monitoring and control is to demonstrate that the validated and specified sterilization process has been delivered to the product.
10.2 There shall be evidence through measurements, supplemented as necessary by biological indicators or chemical indicators, that the sterilization process was delivered within the defined tolerances (see also 9.4.3).
10.3 Data shall be recorded to demonstrate the attainment of process parameters.
10.4 All records shall be retained in accordance with 4.2.4.
10.5 If biological indicators are used in routine monitoring, they shall comply with 8.3 a) and b).
10.6 If chemical indicators are used in routine monitoring, they shall comply with ISO 11140-1 and any subsequent parts of ISO 11140 that are applicable to the process.

Best Regards
Michael Fangon

Dear Ludwig,

I came across an article on validation on the MMM website. You can find it on the page: www.mmmgroup.com/e/show_sidebar.asp?id=6: "Statement about the validation of sterilization cycles or the reprocessing of reusable medical devices used in healthcare."

See you,
Wim Renders