BS EN ISO 11137-2:2015 pdf free.STERILIZATION OF HEALTH CARE PRODUCTS – RADIATION – PART 2: ESTABLISHING THE STERILIZATION DOSE.
BS EN ISO 11137-2:2015 specifies methods for determining the minimum dose needed to achieve a specified requirement for sterility and methods to substantiate the use of 25 kGy or 15 kGy as the sterilization dose to achieve a sterility assurance level, SAL, of 10-6. This part of ISO 11137 also specifies methods of sterilization dose audit used to demonstrate the continued effectiveness of the sterilization dose.
BS EN ISO 11137-2:2015 defines product families for sterilization dose establishment and sterilization dose audit.
This part of Iso 11137 describes methods that can be used to establish the sterilization dose in accordance with one of the two approaches specified in 8.2 of ISO 11137-1:2006. The methods used in these approaches are:
— dose setting to obtain a product-specific dose;
— close substantiation to verify a preselected dose of 25 kGy or 15 kGy.
The basis of the dose setting methods described in this part of ISO 11137 (Methods 1 and 2) owe much to the ideas first propounded by TallentireI19II20II21I. Subsequently, standardized protocols were deveiopedl10l[111, which formed the basis of the dose setting methods detailed in the AAMI Recommended Practice for Sterilization by Gamma Radiationl6ll8l.
Methods 1 and 2 and the associated sterilization dose audit procedures use data derived from the inactivation of the microbial population in its natural state on product. The methods are based on a probability model for the inactivation of microbial populations. The probability model, as applied to biohurden made up of a mixture of various microbial species, assumes that each such species has its own unique D10 value. In the model, the probability that an item will possess a surviving microorganism after exposure to a given dose of radiation is defined in terms of the initial number of microorganisms on the item prior to irradiation and the D10 values of the microorganisms. The methods involve performance of tests of sterility on product items that have received doses of radiation lower than the sterilization dose. The outcome of these tests is used to predict the dose needed to achieve a predetermined sterility assurance level (SAL).
This part of Iso 11137 also describes methods that can be used to carry out sterilization dose audits in accordance with ISO 11137-1:2006, Clause 12. Following establishment of the sterilization dose, sterilization dose audits are performed routinely to confirm that the sterilization dose continues to achieve the desired SAL.