ANSI AAMI ST21-1999 pdf free download.Sterilization of health care products– Biological indicators- -Part 2: Biological indicators for ethylene oxide sterilization
1 Scope
This American National Standard provides specific requirements for test organisms and biological indicators (BIs) intended for use in assessing the performance of sterilizers employing pure ethylene oxide gas or admixtures of the gas with diluent gases at sterilizing temperatures within the range of 20° C to 65° C. Compliance with this standard necessitates compliance with ST59, Sterilization of health care products- Biological indicators- -Part 1: General.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of ANSI/AAMI ST21. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on ANSI/AAMI ST21 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. The American National Standards Institute maintains a register of currently valid American National Standards.
ANSI/AAMI ST59:1999, Sterilization of health care products- Biological indicators- Part 1: General
ANSI/AAMI ST44:1992, BIER/EO gas vessels
3 Definitions
For the purposes of this American National Standard, the definitions given in ANSI/AAMI ST59 apply.
4 General
The requirements of ANSI/AAMI ST59 shall apply, except as modified in the subsequent clauses of this American National Standard.
5 Test organisms
The test organisms shall be spores of Bacillus subtilis or other strains or organisms of demonstrated equivalent performance as required by this part of ANSI/AAMI ST21.
NOTES-
1. Bacillus subtilis NCTC (National Collection of Type Cultures [of the U.K. Central Public Health Laboratory]) 10073 and CIP (Collection of the Institut Pasteur) 7718, and B. subtilis ATCC (American Type Culture Collection) 9372 and NRRL (Northern Regional Research L aboratory [of the Northern Uilization Research and Development Division of the U.S. Department of Agriculture]) B 4418 have been found to be suitable.
2. If an organism other than B. subtilis is used, then the suitability of the resistance of the test organism chosen should be determined during process qualification.
6 Suspensions Replicate determinations of the viable test organism count on the same batch of suspension shall be within+35% of the nominal population.
7 Carrier and primary packaging
For specific requirements for the carrier and primary packaging, see ANSI/AAMI ST59, subclause 4.4.
8 Biological indicators (BIs)
8.1 The number of recoverable test organisms on each BI shall be controlled during manufacture to be either within土50% of the nominal population stated by the manufacturer or within the minimum and maximum populations stated by the manufacturer.
8.2 Retrospective determination of the count shall be made by performing a viable test organism count under the manufacturer’s stated culture conditions on a suspension of test organisms obtained by physical removal of the test organisms from the carrier through ultrasonication， shaking with glass beads， or other appropriate validated methods. Counts obtained shall be regarded as acceptable if they are within – 50% and + 300% of the stated value or, if minimum and maximum populations are stated by the manufacturer, within those stated minimum and maximum populations.
8.3 For inoculated carriers and BIs intended for use in routine monitoring, the nominal population shall not be less than 1 X 10° stated in increments no greater than0.1 x 10°. NOTE- -Inoculated carriers and BIs intended for other purposes (e.g, qualification, validation, or other specific tests) could require other nominal populations. Other inoculum levels may be uilized for routine monitoring of industrial ethylene oxide processes, provided that level has been shown to be appropriate during process qualification.
