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Recommendations by the Quality Task Group
[3] Validation (Part 1)

Based on DIN EN 554, validation is "a documented procedure for furnishing, recording and interpreting the requisite results, in order to demonstrate that a process continually meets the given specifications". Expressed in simple terms this means: validation is a complicated procedure during which a process is investigated to establish whether it is continually executed, i.e. also after validation, such that it meets all the QUALITY REQUIREMENTS addressed to the process. Hence validation of a sterilisation process furnishes proof of its suitability and certifies its effectiveness. Validation must be documented.

The purpose of validation is explained as follows in draft DIN 58946-6 of April 1998: "Validation serves to furnish documented proof of the ongoing effectiveness of the sterilisation process under the operating conditions prevailing at the installation site, using the sterile items encountered in routine operation in their respective packaging and with the reference loads used".

In principle all processes should be validated, in cases where each product produced by the process cannot be checked for compliance with the quality requirements (i.e. sterility in this case), as such a test would render it unusable (i.e. unsterile). Therefore EACH PROCESS to be used for sterilisation should also be validated.

Processes upon whose safe execution the health of people depends, hence also sterilisation of medicinal products, must be validated at regular intervals. In the pharmaceutical manufacturing industry validation has been an established practice for a long time now.

DIN EN 554 entitled "Sterilisation of medical devices. Validation and routine monitoring for sterilisation with moist heat" stipulates, inter alia, requirements for monitoring steam sterilisation of medical devices. In the context of this standard and of the Medical Devices Ordinance (MPBetreibV), medical devices are all devices that have been manufactured while taking into account the provisions of MPG and which for this reason must have a CE mark and possibly a 4-digit identification number affixed to them.

This definition will in the future apply to almost all the sterile supplies processed in the CSSD. Furthermore, the steriliser itself is also classified as a medical device and must be operated in accordance with MPG and MPBetrreibV.

The MEDICAL DEVICES OPERATOR ORDINANCE of June 29, 1998 states in Section 4, Para. 2: "Cleaning, disinfection and sterilisation of medical devices must be carried out with validated processes while observing the manufacturer's instructions, so as to ensure that the safety and health of patients, users or third parties are not compromised".

Since an ordinance has a legal character, a different procedure is adopted from that described for cases of violation of a law, and a sentence will be passed by judges if this violation would endanger the safety and health of patients.

A process which is to be validated must demonstrate proof that it is always executed in the same manner within defined limits. Validation must have a basis, e.g. a standard. Processes to be validated should be (fully) automatic.

Processes that are not reproducible, i.e. run differently in each case and thus unpredictably, cannot be validated. Processes that do not comply with the requirements specified in the standards governing them cannot be validated on the basis of these standards.

Validation can be carried out by anyone who possesses the necessary expertise and reliability, meets the prerequisites and disposes of appropriate means and calibrated measuring equipment for proper execution of validation.

Validation confers a whole range of advantages:

• The thermoelectric testing conducted for performance assessment is an exact physical method in which the measuring instruments and sensors used are checked for suitability immediately prior to testing.
• The process complies with DIN EN 554.
• The result is quickly available.
• During the performance assessment it is not only established whether the process is safe, but rather just how safe.
• A large part of the entire surroundings of the steriliser is taken into consideration during evaluation.
• The entire testing procedure is carried out in the CSSD.

If conditions have remained unchanged, thermoelectric testing of the sterilisation process should be conducted once yearly with previously calibrated sensors. If conditions have changed, a performance assessment must be carried out again even before one year has elapsed.

¹ This articles focuses in particular on the general principles of validation. In the next edition of Central Service the individual steps needed to implement validation will be outlined based on the example of a case.