【BS英國標(biāo)準(zhǔn)】BS EN 866-2-1998 Biological systems for testing sterilizers and sterilization processes Part 2. Particular systems for use in ethylene oxide s

british standardbiological systems for testing sterilizers and sterilization processespart 2. particular systems for use in ethylene oxide sterilizersthe european standard en 866-2 : 1997 has the status of abritish standardics 11.080| bs en866-2 : 1998|no copying without bsi permission except as permitted by copyright lawbs en 866-2 : 1998committees responsible for thisbritish standardthe preparation of this british standard was entrusted by technical committee lbi/35, sterilizers, autoclaves and disinfectors, to subcommittee lbi/35/3, sterilization indicators, upon which the following bodies were represented:abhi special interest section (sterilizers and disinfectors) association of british healthcare industriesblwa ltd (the association of the laboratory supply industry) department of health (medical devices agency)european sterilization packaging association (uk) medical sterile products associationpublic health laboratory serviceroyal college of pathologistsroyal pharmaceutical society of great britainthis british standard, having been prepared under the direction of the sector board for materials and chemicals, was published under the authority of the standards board and comes into effect on 15 march 1998bsi 1998the following bsi references relate to the work on this standard:committee reference lbi/35/3draft for comment 95/121172 dcisbn 0 580 28378 xamd. no.datetext affectedamendments issued since publicationbs en 866-2 : 1998national forewordthis part of bs en 866 has been prepared by subcommittee lbi/35/3 and is the english language version of en 866-2 : 1997 biological systems for testing sterilizers and sterilization processes part 2: particular systems for use in ethylene oxide sterilizers, published by the european committee for standardization (cen).cross-referencepublication referred to corresponding british standarden 866-1 : 1997bs en 866 biological systems for testing sterilizers and sterilization processespart 1 : 1997 general requirementscompliance with a british standard does not of itself confer immunity from legal obligations.summary of pagesthis document comprises a front cover, an inside front cover, pages i and ii, the en title page, pages 2 to 6, an inside back cover and a back cover.bsi 1998iiiblankeuropean standarden 866-2norme europe enneeuropa ische normfebruary 1997ics 11.080descriptors: medical equipment, sterilizers, sterilization, ethylene oxide, bioassay, specifications, biological indicatorsenglish versionbiological systems for testing sterilizers and sterilization processes part 2: particular systems for use in ethylene oxide sterilizerssyste mes biologiques pour lessai des ste rilisateurset les proce de s de ste rilisation partie 2: syste mes particuliers destine s a e tre utilise s dans desste rilisateurs a loxyde de thyle nebiologische systeme fu r die pru fung von sterilisatoren und sterilisationsverfahren teil 2: spezielle systeme fu r den gebrauch in ethylenoxid-sterilisatorenthis european standard was approved by cen on 1997-01-10. cen members are bound to comply with the cen/cenelec internal regulations which stipulate the conditions for giving this european standard the status of a national standard without any alteration.up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the central secretariat or to any cen member.this european standard exists in three official versions (english, french, german). a version in any other language made by translation under the responsibility of a cen member into its own language and notified to the central secretariat has the same status as the official versions.cen members are the national standards bodies of austria, belgium, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg, netherlands, norway, portugal, spain, sweden, switzerland and united kingdom.ceneuropean committee for standardization comite europe en de normalisation europa isches komitee fu r normungcentral secretariat: rue de stassart 36, b-1050 brussels1997 copyright reserved to cen members.ref. no. en 866-2 : 1997 epage 5en 866-2 : 1997bsi 1998forewordthis european standard has been prepared by technical committee cen/tc 102, sterilizers for medical purposes, the secretariat of which is held by din.this standard is one of a series of european standards concerned with biological systems for testingsterilizers. these european standards are:en 866-1biological systems for testing sterilizers and sterilization processes part 1: general requirementsen 866-2biological systems for testing sterilizers and sterilization processes part 2: particular systems for use in ethylene oxide sterilizersen 866-3biological systems for testing sterilizers and sterilization processes part 3: particular systems for use in moist heat sterilizerspren 866-4biological systems for testing sterilizers and sterilization processes part 4: particular systems for use in irradiation sterilizerspren 866-5biological systems for testing sterilizers and sterilization processes part 5: particular systems for use in low temperature steam and formaldehyde sterilizerspren 866-6biological systems for testing sterilizers and sterilization processes part 6: particular systems for use in dry heat sterilizerspren 866-7biological systems for testing sterilizers and sterilization processes part 7: particular requirements for self-contained biological indicator systems for use in moist heat sterilizerspren 866-8biological systems for testing sterilizers and sterilization processes part 8: particular requirements for self-contained biological indicator systems for use in ethylene oxide sterilizersin addition, cen/tc 102 working group 7 has prepared a series of european standards describingnon-biological indicators for use in sterilizers. theseeuropean standards are:en 867-1non-biological systems for use in sterilizers part 1: general requirementsen 867-2non-biological systems for use in sterilizers part 2: process indicators (class a)en 867-3non-biological systems for use in sterilizers part 3: specification for class b indicators for use in the bowie and dick testthis european standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by august 1997, and conflicting national standards shall be withdrawn at the latest by august 1997.this european standard has been prepared under a mandate given to cen by the european commission and the european free trade association, and supports essential requirements of eu directive(s).according to the cen/cenelec internal regulations, the national standards organizations of the following countries are bound to implement this european standard: austria, belgium, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg, netherlands, norway, portugal, spain, sweden, switzerland and the united kingdom.contentspageforeword 2introduction 31 scope 32 normative references 33 definitions 34 general requirements 35 test organisms 36 population of test organisms 37 carriers 48 resistance 4annexesa (normative) method for the determination of resistance toethylene oxide sterilization 5b (informative) bibliography 6introductionthis standard specifies the performance requirements for biological indicators supplied ready for use, and for suspensions of test organisms supplied either for the preparation of biological indicators or for the inoculation of product for use in validation studies on, and routine monitoring of, ethylene oxide sterilization processes. the use of the indicators specified in this standard is described in en 550.the biological indicators specified in this standard are not intended for use in any process other than ethylene oxide sterilization. the use of an inappropriate biological indicator in a process other than that stated by the manufacturer can give dangerously misleading results.the use of a biological system for testing a sterilization process does not allow necessarily the same level of sensitivity in response to inadequate levels of all the critical variables of the process.the performance of a biological indicator can be affected by the conditions of storage prior to use, the methods of use, and the techniques employed after exposure to the process. for these reasons, the recommendations of the manufacturer for storage and use should be followed and biological indicators should be transferred to the specified recovery conditions as soon as possible after exposure to the process. biological indicators should not be used beyond any expiry date stated by the manufacturer.biological indicators should always be used in combination with physical and/or chemical monitoring in demonstrating the efficacy of a sterilization process. when a physico-chemical variable of a sterilization process is outside its specified limits, a sterilization cycle should always be regarded as unsatisfactory, irrespective of the results obtained from the biological indicators. (see also en 550).1 scopethis part of en 866 specifies requirements for inoculated carriers and biological indicators intended for use in assessing the performance of sterilizers and sterilization processes employing ethylene oxide gas as the sterilant. these are intended for use in sterilizers employing pure ethylene oxide gas or admixtures ofthe gas with diluent gases, over a sterilizing temperature range of 20 8c to 65 8c.note. pren 1422 specifies the performance and test requirements for ethylene oxide sterilizers. en 550 specifies the requirementsfor the validation and routine monitoring of ethylene oxide sterilization.2 normative referencesthis european standard incorporates by dated or undated references provisions from other publications. these normative references are cited at theappropriate places in the text and the publications are listed hereafter. for dated references, subsequent amendments to or revisions of any of these publications apply to this european standard onlywhen incorporated in it by amendment or revision. for undated references the latest edition of the publication referred to applies.en 866-1 : 1997 biological systems for testing sterilizers and sterilization processes part 1: general requirements3 definitionsfor the purposes of this standard, the definitions given in en 866-1 apply.4 general requirementsthe requirements of en 866-1 shall apply.5 test organismsthe test organism shall be spores of bacillus subtilis var. niger or other strains or organisms of demonstrated equivalent performance as required by this standard.note. bacillus subtilis nctc 10073, dsm 2277, atcc 9372 orcip 7718 have been found to be suitable.6 population of test organisms6.1 replicate determinations of the viable count on the same batch of suspension shall be within 35 % of the nominal population.6.2 the number of recoverable test organisms on each biological indicator shall be controlled during manufacture to be either within 50 % of the nominal population stated by the manufacturer, or within the minimum and maximum populations stated by the manufacturer.6.3 retrospective determination of the count shall be made by performing a viable count under the 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 250 % and +300 % of the nominal population stated by the manufacturer or the mid-point between the minimum and maximum populations stated by the manufacturer.note. guidance on the selection and validation of methods for the removal of micro-organisms from the carrier is given inen 1174-2.6.4 for inoculated carriers or biological indicators intended for use in routine monitoring, the nominal number of spores shall be not less than 1 3 106 per unit and shall be stated in increments not greater than0,1 3 106.note. inoculated carriers and/or biological indicators supplied for other purposes, e.g. qualification, validation and other specific tests, may require other nominal populations.7 carriers7.1 the suitability of the carrier for use in ethylene oxide sterilization processes shall be demonstrated in accordance with the requirements of 6.1 and 6.2 of en 866-1 : 1997 and annex a of this standard.7.2 the exposure conditions to be used to establish compliance shall be: temperature: not less than 55 8c; relative humidity: not less than 70 %; gas concentration: not less than 800 mg/l; exposure time: not less than 6 h.note. these conditions have been selected to represent a realistic challenge to the carrier whilst remaining within the practical limits of an ethylene oxide sterilization process.8 resistance8.1 generalthe manufacturer shall state the d value of each batch of biological indicators or inoculated carriers to an accuracy of 0,5 min.8.2 biological indicators and inoculatedcarriers intended for use in routine monitoring8.2.1 the d values obtained for the spore population on the inoculated carriers shall be not less than12,5 min when exposed to (600 30) mg/l ethylene oxide at (30 1) 8c and (60 10) % relative humidity, and/or not less than 2,5 min when exposed to(600 30) mg/l ethylene oxide at (54 1) 8c and(60 10) % relative humidity, determined in accordance with the method given in annex a. (see 10.2 ofen 866-1 : 1997).note. a temperature coefficient of inactivation of the test organism of not less than 2 can be used to relate these d values to other temperatures when all other conditions remain constant.8.2.2 the d value obtained by the two methods shall be such that the higher value obtained does not exceed the lower value by more than 50 % of the lower value.8.3 biological indicators and inoculated carriers intended for use in validation, qualification and other specific testsnote. biological indicators and inoculated carriers intended for use in validation, qualification and other specific tests have no specific requirements for the population or resistance of test organisms, to allow users flexibility in devising test programs. the d value and population are determined and stated (see 6.3 and 6.4, 8.1, 8.3a, 8.3b).when the purchaser specifies requirements other than those in 8.2 for biological indicators and inoculated carriers intended for use in validation, qualification and other specific tests, the following shall apply.a) the d values shall be determined by exposure to(600 30) mg/l ethylene oxide at (30 1) 8c and (60 10) % relative humidity, and by exposure to (600 30) mg/l ethylene oxide at (54 1) 8c and(60 10) % relative humidity, in accordance with the methods given in annex a.b) the d value obtained shall be such that the higher value obtained does not exceed the lower value by more than 50 % of the lower value. both d values shall be stated.annex a (normative)method for the determination of resistance to ethylene oxide sterilizationa.1 apparatus: ethylene oxide biological indicator resistometera.1.1 the equipment shall be capable of maintaining the conditions given in table a.1, within the limits given, for exposure periods of between 1 min and120 min to an accuracy of 10 s. in addition, the equipment shall be capable of sustaining an exposure of not less than 6 h.table a.1 conditionsvariablefor resistance studies(see clause 8)for carrier studies(see clause 7)ethylene oxide(600 30) mg/lnot less than800 mg/ltemperature(30 1) 8c or(54 1) 8cnot less than 55 8crelative humidity(60 10) %not less than 70 %note 1. forced circulation may be required to maintain the conditions in the resistometer chamber uniform within the specified limits.note 2. resistometers intended for use with mixtures of ethylene oxide and inert gases may be required to withstand high internal pressures, e.g. 650 kpa.a.1.2 the equipment shall be provided with means to evacuate the reaction chamber to less than 10 kpa within 2 min, to permit adequate air removal prior to admission of the sterilant and to exhaust the sterilantat the end of the exp