Irradiation Sterilization
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Irradiation sterilization of a medical device means product exposure to a definite and documented radiation field, at a well-defined absorbed dose, validated to be effective together with the manufacturer.

The requirements for validation and routine control of radiation sterilization of medical devices are previewed in EN 552: 1994.

The absorbed dose is a measure of the physical interaction between the radiation and (any) substance. Interaction with microorganisms results in their elimination, if the absorbed dose is sufficiently high.

To identify the sterilization dose some ways are established, all of them based on microbiological tests.

The traditional sterilization dose of 25 kGy is mentioned in European Pharmacopoeia but has to be documented.
Good Manufacturing Practice in medical devices' production line may reduce this dose.

The responsibilities concerning the sterile status of an item are shared between the manufacturer (that has to conserve the manufacturing conditions from the validation sterilization moment) and the irradiation facility.
The irradiator responsibility is to deliver the prescribed and validated dose and to document it.
That's why measuring the absorbed dose is most important obligation of an irradiation facility. For each recommended dosimetric system there is an ISO standard specifying manufacturing, measuring and data interpretation.
To be valid, a calibrated dosimetric system must be traceable to a national or international primary standard.

IRASM use ECB (ethanol chlor benzene) dosimeter, traceable at National Physical Laboratory - U.K. trough RISO High Dose Reference Laboratory - Denmark.

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