SIST EN 13727:2012
(Main)Chemical disinfectants and antiseptics - Quantitative suspension test for the evaluation of bactericidal activity in the medical area - Test method and requirements (phase 2, step 1)
Chemical disinfectants and antiseptics - Quantitative suspension test for the evaluation of bactericidal activity in the medical area - Test method and requirements (phase 2, step 1)
This European Standard specifies a test method and the minimum requirements for bactericidal activity of chemical disinfectant and antiseptic products that form a homogeneous, physically stable preparation when diluted with hard water - or in the case of ready-to-use products - with water. Products can only be tested at a concentration of 80 % or less (97 % with a modified method for special cases) as some dilution is always produced by adding the test organisms and interfering substance.
This European Standard applies to products that are used in the medical area in the fields of hygienic handrub, hygienic handwash, surgical handrub, surgical handwash, instrument disinfection by immersion, and surface disinfection by wiping, spraying, flooding or other means.
This European Standard applies to areas and situations where disinfection or antisepsis is medically indicated. Such indications occur in patient care, for example:
- in hospitals, in community medical facilities and in dental institutions;
- in clinics of schools, of kindergartens and of nursing homes;
and may occur in the workplace and in the home. It may also include services such as laundries and kitchens supplying products directly for the patients.
NOTE 1 The method described is intended to determine the activity of commercial formulations or active substances under the conditions in which they are used.
NOTE 2 This method corresponds to a phase 2 step 1 test (see annex E).
NOTE 3 This method cannot be used to evaluate the activity of products against Legionalla species in watersystems and mycobacteria.
EN 14885 specifies in detail the relationship of the various tests to one another and to "use recommendation".
Chemische Desinfektionsmittel und Antiseptika - Quantitativer Suspensionsversuch zur Bestimmung der bakteriziden Wirkung im humanmedizinischen Bereich - Prüfverfahren und Anforderungen (Phase 2, Stufe 1)
Diese Europäische Norm legt ein Prüfverfahren für und die Mindestanforderungen an die bakterizide Wirkung von chemischen Desinfektionsmitteln und Antiseptika fest, die bei Verdünnung mit Wasser standardisierter Härte als homogene, physikalisch stabile Zubereitung vorliegen, bzw. bei gebrauchsfertigen Produkten bei der Verdünnung mit Wasser. Die Produkte können nur bei einer Konzentration von 80 % oder weniger (97 % bei einem modifizierten Verfahren für Sonderfälle) geprüft werden, da durch Zugabe der Prüfkeime und der Belastungssubstanz immer eine gewisse Verdünnung bewirkt wird.
Diese Europäische Norm gilt für Produkte, die im medizinischen Bereich auf den Gebieten der hygienischen Händedesinfektion, hygienischen Händewaschung, chirurgischen Händedesinfektion, chirurgischen Hände¬waschung, Instrumentendesinfektion durch Eintauchen und Oberflächendesinfektion durch Abwischen, Besprühen, Überfluten oder auf sonstige Weise verwendet werden.
Diese Europäische Norm gilt für Bereiche und unter Bedingungen, wo eine Desinfektion oder Antiseptik aus medizinischen Gründen angezeigt ist. Indikationen dieser Art liegen z. B. bei der Patientenbetreuung in:
- Krankenhäusern, kommunalen medizinischen Einrichtungen und im Dentalbereich;
- medizinischen Einrichtungen in Schulen, Kindergärten und Heimen;
vor und können auch am Arbeitsplatz und im häuslichen Bereich gegeben sein. Eingeschlossen sein können auch Einrichtungen wie Wäschereien und Küchen, die der direkten Versorgung der Patienten dienen.
ANMERKUNG 1 Das beschriebene Verfahren dient zur Bestimmung der Wirkung handelsüblicher Zubereitungen oder Wirkstoffe unter den Bedingungen, unter denen sie angewendet werden.
ANMERKUNG 2 Dieses Verfahren entspricht einer Prüfung der Phase 2, Stufe 1.
ANMERKUNG 3 Dieses Verfahren kann nicht angewendet werden, um die Wirkung von Produkten gegen Legionella in wasserführenden Systemen, gegen Mykobakterien und bakterielle Sporen zu bewerten.
EN 14885 legt im Einzelnen die Beziehung der verschiedenen Prüfungen untereinander sowie zu den 'Anwendungsempfehlungen' fest.
Désinfectants chimiques et antiseptiques - Essai quantitatif de suspension pour l'évaluation de l'activité bactéricide en médecine - Méthode d'essai et prescriptions (phase 2, étape 1)
La présente Norme européenne spécifie une méthode d’essai et les prescriptions minimales relatives à l’activité bactéricide des produits antiseptiques et désinfectants chimiques qui forment une préparation homogène, physiquement stable, lorsqu’ils sont dilués dans de l'eau dure ou - dans le cas de produits prêts à l’emploi - dans l’eau. Les produits ne peuvent être soumis à l’essai qu’à la concentration de 80 % (97 % avec une méthode modifiée pour les cas particuliers) ou à des concentrations inférieures, car l’ajout des microorganismes d’essai et de la substance interférente s’accompagne forcément d’une dilution.
La présente Norme européenne s'applique aux produits utilisés en médecine dans la friction hygiénique des mains, le lavage hygiénique des mains, la friction chirurgicale des mains, le lavage chirurgical des mains, la désinfection des instruments par immersion, ainsi que la désinfection des surfaces par essuyage, pulvérisation, inondation ou d'autres moyens.
La présente Norme européenne s'applique aux zones et aux situations où la désinfection ou l'antisepsie est médicalement indiquée. Ces indications se rencontrent lors de soins apportés aux patients, par exemple :
- dans des hôpitaux, centres de soins médicaux et cabinets dentaires ;
- dans des infirmeries d’écoles, de jardins d’enfants et de maisons de retraite ;
et peuvent aussi se rencontrer sur les lieux de travail ou à domicile. Elles peuvent également concerner des services tels que des blanchisseries et des cuisines qui fournissent des produits directement aux patients.
NOTE 1 La méthode décrite vise à déterminer l’activité des formulations commerciales ou des substances actives dans les conditions dans lesquelles elles sont utilisées.
NOTE 2 Cette méthode correspond à un essai de phase 2, étape 1.
NOTE 3 Cette méthode ne peut pas être utilisée pour évaluer l'activité des produits vis-à-vis de Legionella dans les réseaux d'eau, des mycobactéries et des spores de bactéries.
L'EN 14885 spécifie en détail la relation entre les différents essais et les « recommandations d'emploi ».
Kemična razkužila in antiseptiki - Kvantitativni suspenzijski preskus za vrednotenje baktericidnega delovanja kemičnih razkužil in antiseptikov v humani medicini - Preskusna metoda in zahteve (faza 2, stopnja 1)
Ta evropski standard določa preskusno metodo in minimalne zahteve za baktericidno delovanje kemičnih razkužil in antiseptikov, ki tvorijo homogen, fizikalno stabilen pripravek, če so razredčeni s trdo vodo ali, pri proizvodih, ki so pripravljeni za uporabo, z vodo. Proizvode je mogoče preskušati samo pri 80-odstotni ali nižji koncentraciji (s prilagojeno metodo v posebnih primerih 97-odstotni), ker dodajanje preskusnih organizmov in moteče snovi vedno povzroči razredčenje. Ta evropski standard velja za proizvode, ki se uporabljajo na področju zdravstva pri higienskem drgnjenju rok, higienskem umivanju rok, kirurškem drgnjenju rok, kirurškem umivanju rok, dezinfekciji instrumentov s potapljanjem in površinski dezinfekciji z brisanjem, pršenjem, zalivanjem ali na druge načine. Ta evropski standard se uporablja za področja in primere, ko obstajajo zdravniške indikacije za dezinfekcijo ali antisepso. Te indikacije se pojavljajo pri negi bolnikov, na primer: v bolnišnicah, skupnih zdravstvenih in zobozdravstvenih ustanovah; v klinikah šol, vrtcev in domov za starejše; in lahko nastanejo na delovnem mestu ali doma. Vključujejo lahko tudi storitve, kot so pralnice in kuhinje, ki proizvode neposredno dostavljajo pacientom.
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Chemische Desinfektionsmittel und Antiseptika - Quantitativer Suspensionsversuch zur Bestimmung der bakteriziden Wirkung im humanmedizinischen Bereich - Prüfverfahren und Anforderungen (Phase 2, Stufe 1)Désinfectants chimiques et antiseptiques - Essai quantitatif de suspension pour l'évaluation de l'activité bactéricide en médecine - Méthode d'essai et prescriptions (phase 2, étape 1)Chemical disinfectants and antiseptics - Quantitative suspension test for the evaluation of bactericidal activity in the medical area - Test method and requirements (phase 2, step 1)11.080.20Dezinfektanti in antiseptikiDisinfectants and antisepticsICS:Ta slovenski standard je istoveten z:EN 13727:2012SIST EN 13727:2012en,de01-junij-2012SIST EN 13727:2012SLOVENSKI
STANDARDSIST EN 13727:20041DGRPHãþD
SIST EN 13727:2012
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 13727
May 2012 ICS 11.080.20 Supersedes EN 13727:2003English Version
Chemical disinfectants and antiseptics - Quantitative suspension test for the evaluation of bactericidal activity in the medical area - Test method and requirements (phase 2, step 1)
Antiseptiques et désinfectants chimiques - Essai quantitatif de suspension pour l'évaluation de l'activité bactéricide en médecine - Méthode d'essai et prescriptions (phase 2, étape 1)
Chemische Desinfektionsmittel und Antiseptika - Quantitativer Suspensionsversuch zur Bestimmung der bakteriziden Wirkung im humanmedizinischen Bereich - Prüfverfahren und Anforderungen (Phase 2, Stufe 1) This European Standard was approved by CEN on 9 March 2012.
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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13727:2012: ESIST EN 13727:2012
EN 13727:2012 (E) 2 Contents Page Foreword .4Introduction .51 Scope .62 Normative references .63 Terms and definitions .64 Requirements .75 Test method .85.1 Principle .85.2 Materials and reagents .85.2.1 Test organisms .85.2.2 Culture media and reagents .95.3 Apparatus and glassware . 125.3.1 General . 125.3.2 Usual microbiological laboratory equipment . 125.4 Preparation of test organism suspensions and product test solutions . 135.4.1 Test organism suspensions (test and validation suspension) . 135.4.2 Product test solutions . 155.5 Procedure for assessing the bactericidal activity of the product . 155.5.1 General . 155.5.2 Dilution-neutralization method . 175.5.3 Membrane filtration method . 195.5.4 Modified method for ready-to-use products . 215.6 Experimental data and calculation. 225.6.1 Explanation of terms and abbreviations . 225.6.2 Calculation . 235.7 Verification of methodology . 285.7.1 General . 285.7.2 Control of weighted mean counts . 285.7.3 Basic limits . 285.8 Expression of results and precision . 295.8.1 Reduction . 295.8.2 Control of active and non-active product test solution (5.4.2) . 295.8.3 Limiting test organism and bactericidal concentration . 295.8.4 Precision, repetitions . 295.9 Interpretation of results - conclusion . 305.9.1 General . 305.9.2 Bactericidal activity for handrub and handwash products . 305.9.3 Bactericidal activity for instrument disinfection products . 305.9.4 Bactericidal activity for surface disinfection products. 305.9.5 Qualification for certain fields of application . 305.10 Test report . 30Annex A (informative)
Referenced strains in national collections . 33Annex B (informative)
Neutralizers and rinsing liquids . 34Annex C (informative)
Graphical representation of test procedures . 36Annex D (informative)
Example of a typical test report . 44Annex E (informative)
Precision of the test result . 48SIST EN 13727:2012
EN 13727:2012 (E) 3 Annex ZA (informative)
Relationship between this European Standard and the Essential Requirements of EU Directive 93/42/EEC . 51Bibliography . 52 SIST EN 13727:2012
EN 13727:2012 (E) 4 Foreword This document (EN 13727:2012) has been prepared by Technical Committee CEN/TC 216 “Chemical disinfectants and antiseptics”, the secretariat of which is held by AFNOR. This 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 November 2012, and conflicting national standards shall be withdrawn at the latest by November 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 13727:2003. This document 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). For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document. The document was revised to adapt it to the latest state of science, to correct errors and ambiguities, to harmonize the structure and wording with other tests of CEN/TC 216 existing or in preparation and to improve the readability of the standard and thereby make it more understandable. The following is a list of significant technical changes since the last edition: • The scope was expanded for the following fields of application within the medical area i.e. products for surgical and/or all hygienic handrub and/or hand wash and disinfectants for other surface then instrument surfaces. • "Obligatory test conditions" were replaced by "minimum test conditions" (test temperatures and contact times can be chosen within limits) that have to be performed to pass the test. • An additional modified method is described to test ready-to-use products in a higher concentration than 80%, i.e. 97%. • The Annex ZA was reformulated to more accurately describe the relationship with the medical device directive. Data obtained using the former version of EN 13727 may still be used. Data obtained by using the prEN 12054 should not be used as this project was abandoned in 2001.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 13727:2012
EN 13727:2012 (E) 5 Introduction This European Standard specifies a suspension test for establishing whether a chemical disinfectant or an antiseptic has a bactericidal activity in the area and fields described in the scope. This laboratory test takes into account practical conditions of application of the product including contact time, temperature, test organisms and interfering substances, i.e. conditions which may influence its action in practical situations. Each utilization concentration of the chemical disinfectant or antiseptic found by this test corresponds to the chosen experimental conditions.
SIST EN 13727:2012
EN 13727:2012 (E) 6 1 Scope This European Standard specifies a test method and the minimum requirements for bactericidal activity of chemical disinfectant and antiseptic products that form a homogeneous, physically stable preparation when diluted with hard water, or - in the case of ready-to-use products - with water. Products can only be tested at a concentration of 80 % or less (97 % with a modified method for special cases) as some dilution is always produced by adding the test organisms and interfering substance.
This European Standard applies to products that are used in the medical area in the fields of hygienic handrub, hygienic handwash, surgical handrub, surgical handwash, instrument disinfection by immersion, and surface disinfection by wiping, spraying, flooding or other means. This European Standard applies to areas and situations where disinfection or antisepsis is medically indicated. Such indications occur in patient care, for example: in hospitals, in community medical facilities and in dental institutions; in clinics of schools, of kindergartens and of nursing homes; and may occur in the workplace and in the home. It may also include services such as laundries and kitchens supplying products directly for the patients. NOTE 1 The method described is intended to determine the activity of commercial formulations or active substances under the conditions in which they are used. NOTE 2 This method corresponds to a phase 2 step 1 test. NOTE 3 This method cannot be used to evaluate the activity of products against Legionella in watersystems against mycobacteria and against bacterial spores. EN 14885 specifies in detail the relationship of the various tests to one another and to “use recommendations”. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12353, Chemical disinfectants and antiseptics — Preservation of test organisms used for the determination of bactericidal (including Legionella), mycobactericidal, sporicidal, fungicidal and virucidal (including bacteriophages) activity EN 14885, Chemical disinfectants and antiseptics — Application of European Standards for chemical disinfectants and antiseptics 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 14885 apply. SIST EN 13727:2012
EN 13727:2012 (E) 7 4 Requirements The product shall demonstrate at least a 5 decimal log (lg) reduction (for hygienic hand wash at least a 3 lg reduction), when tested in accordance with Table 1 and Clause 5. Table 1 — Minimum and additional test conditions Test Conditions Hygienic handrub and handwash Surgical handrub and handwash Instrument disinfection Surface disinfection Minimum spectrum of test organisms
P. aeruginosa, S. aureus, E. hirae, E. coli K12 P. aeruginosa, S. aureus, E. hirae, E. coli K12 P. aeruginosa, S. aureus, E. hirae, when temperature is
40 °C or higher: only
E. faecium P. aeruginosa, S. aureus, E. hirae
additional Any relevant test organism Test temperature according to the manufacturer’s recommendation, but between
20 °C and 20 °C 20 °C and 20 °C 20 °C and 70 °C 4°C and 30 °C Contact time
according to the manufacturer’s recommendation
but between but no longer than
30 s and 60 s 1 min and 5 min 60 min 5 min or
60 min a Interfering substance
clean conditions
0,3 g/l bovine albumin solution (hygienic handrub) b 0,3 g/l bovine albumin solution (surgical handrub) b 0,3 g/l bovine albumin solution
and/or 0,3 g/l bovine albumin solution
and/or dirty conditions 3,0 g/l bovine albumin solution plus 3,0 ml/l erythrocytes (hygienic handwash) c 3,0 g/l bovine albumin solution plus 3,0 ml/l erythrocytes (surgical handwash) c
3,0 g/l bovine
albumin solution plus 3,0 ml/l erythrocytes
3,0 g/l bovine albumin solution plus 3,0 ml/l erythrocytes additional clean or dirty;
any relevant substance clean or dirty; any relevant substance any relevant substance any relevant substance a The contact times for surface disinfectants stated in this table are chosen on the basis of the practical conditions of the product. The recommended contact time for the use of the product is within the responsibility of the manufacturer. Products intended to disinfect surfaces that are likely to come into contact with the patient and / or the medical staff and surfaces, which are frequently touched by different people, leading to the transmission of microorganisms to the patient, shall be tested with a contact time of maximum 5 min. The same applies where the contact time of the product shall be limited for practical reasons. Products for other surfaces than stated above may be tested with a contact time of maximum 60 min.
b hygienic and surgical handrub shall be tested as a minimum under clean conditions.
c hygienic and surgical handwash shall be tested as a minimum under dirty conditions.
NOTE For the additional conditions, the concentration defined as a result can be lower than the one obtained under the minimum test conditions.
SIST EN 13727:2012
EN 13727:2012 (E) 8 5 Test method 5.1 Principle 5.1.1 A sample of the product as delivered and/or diluted with hard water (or water for ready to use products) is added to a test suspension of bacteria in a solution of an interfering substance. The mixture is maintained at one of the temperatures and the contact times specified in Clause 4 and 5.5.1.1. At the end of this contact time, an aliquot is taken; the bactericidal and/or the bacteriostatic action in this portion is immediately neutralized or suppressed by a validated method. The method of choice is dilution-neutralization. If a suitable neutralizer cannot be found, membrane filtration is used. The numbers of surviving bacteria in each sample are determined and the reduction is calculated. NOTE Handwash products are always prediluted with hard water (5.2.2.7). The resulting solution is regarded as a ready-to-use product (5.4.2). 5.1.2 The test is performed using Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae and for certain product types Escherichia coli K12 as test-organisms (Clause 4, Table 1). 5.1.3 Other contact times and temperatures within the limits specified in Clause 4, Table 1 may be used. Additional interfering substances and test organisms may be used. 5.2 Materials and reagents 5.2.1 Test organisms The bactericidal activity shall be evaluated using the following strains as test organisms selected according to Clause 4 (Table 1)1) : a) Escherichia coli K12, NCTC 10538
b) Pseudomonas aeruginosa, ATCC 15442
c) Staphylococcus aureus, ATCC 6538
d) Enterococcus hirae, ATCC 10541
e) Enterococcus faecium, ATCC 6057
NOTE See Annex A for strain reference in some other culture collections. The required incubation temperature for these test organisms is 36 °C ± 1 °C or 37 °C ± 1 °C (5.3.2.3). The same temperature (either 36 °C or 37 °C) shall be used for all incubations performed during a test and its control and validation. If additional test organisms are used, they shall be incubated under optimum growth conditions (temperature, time, atmosphere, media) noted in the test report. If the additional test organisms selected do not correspond to the specified strains, their suitability for supplying the required inocula shall be verified. If these additional test organisms are not classified at a reference centre, their identification characteristics shall be stated. In addition, they shall be held by the testing laboratory or national culture collection under a reference for five years.
1) The NCTC and ATCC numbers are the collection numbers of strains supplied by these culture collections. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of the product named. SIST EN 13727:2012
EN 13727:2012 (E) 9 5.2.2 Culture media and reagents 5.2.2.1 General All weights of chemical substances given in this European Standard refer to the anhydrous salts. Hydrated forms may be used as an alternative, but the weights required shall be adjusted to allow for consequent molecular weight differences. The reagents shall be of analytical grade and/or appropriate for microbiological purposes. They shall be free from substances that are toxic or inhibitory to the test organisms. NOTE 1 To improve reproducibility, it is recommended that commercially available dehydrated material is used for the preparation of culture media. The manufacturer's instructions relating to the preparation of these products should be rigorously followed.
NOTE 2 For each culture medium and reagent, a time limitation for use should be fixed.
All specified pH values are measured at 20 °C ± 1 °C. 5.2.2.2 Water The water shall be freshly glass-distilled water and not demineralized water. If distilled water of adequate quality is not available, water for injections (see bibliographic reference [1]) may be used. Sterilize in the autoclave [5.3.2.1a)]. Sterilization is not necessary if the water is used e.g. for preparation of culture media and subsequently sterilized.
NOTE See 5.2.2.7 for the procedure to prepare hard water. 5.2.2.3 Tryptone Soya Agar (TSA) Tryptone soya agar, consisting of: Tryptone, pancreatic digest of casein 15,0 gSoya peptone, papaic digest of Soybean meal 5,0 gSodium chloride (NaCl) 5,0 gAgar 15,0 gWater (5.2.2.2) to 1 000,0 mlSterilize in the autoclave [5.3.2.1 a)]. After sterilization the pH (5.3.2.4) of the medium shall be equivalent to 7,2 ± 0,2.
NOTE In case of encountering problems with neutralization (5.5.1.2 and 5.5.1.3) it may be necessary to add neutralizer to TSA. Annex B gives guidance on the neutralizers that may be used. It is recommended not to use a neutralizer that causes opalescence in the agar. SIST EN 13727:2012
EN 13727:2012 (E) 10 5.2.2.4 Diluent Tryptone sodium chloride solution, consisting of: Tryptone, pancreatic digest of casein 1,0 gSodium chloride 8,5 gWater (5.2.2.2) to 1 000,0 ml Sterilize in the autoclave [5.3.2.1 a)]. After sterilization, the pH (5.3.2.4) of the diluent shall be equivalent to 7,0 ± 0,2.
5.2.2.5 Neutralizer The neutralizer shall be validated for the product being tested in accordance with 5.5.1.2, 5.5.1.3 and 5.5.2. It shall be sterile. NOTE Information on neutralizers that have been found to be suitable for some categories of products is given in Annex B. 5.2.2.6 Rinsing liquid (for membrane filtration) The rinsing liquid shall be validated for the product being tested in accordance with 5.5.1.2, 5.5.1.3 and 5.5.3. It shall be sterile, compatible with the filter membrane and capable of filtration through the filter membrane under the test conditions described in 5.5.3. NOTE Information on rinsing liquids that have been found to be suitable for some categories of products is given in Annex B. 5.2.2.7 Hard water for dilution of products For the preparation of 1 l of hard water, the procedure is as follows: prepare solution A: dissolve 19,84 g magnesium chloride (MgCl2) and 46,24 g calcium chloride (CaCl2) in water (5.2.2.2) and dilute to 1 000 ml. Sterilize by membrane filtration (5.3.2.7) or in the autoclave [5.3.2.1 a)]. Autoclaving – if used - may cause a loss of liquid. In this case make up to 1 000 ml with water (5.2.2.2) under aseptic conditions. Store the solution in the refrigerator (5.3.2.8) for no longer than one month; prepare solution B: dissolve 35,02 g sodium bicarbonate (NaHCO3) in water (5.2.2.2) and dilute to 1000 ml. Sterilize by membrane filtration (5.3.2.7). Store the solution in the refrigerator (5.3.2.8) for no longer than one week; place 600 ml to 700 ml of water (5.2.2.2) in a 1 000 ml volumetric flask (5.3.2.12) and add 6,0 ml (5.3.2.9) of solution A, then 8,0 ml of solution B. Mix and dilute to 1 000 ml with water (5.2.2.2). The pH (5.3.2.4) of the hard water shall be 7,0 ± 0,2. (5.3.2.4). If necessary, adjust the pH by using a solution of approximately 40 g/l (about 1 mol/l) of sodium hydroxide (NaOH) or approximately 36,5 g/l (about 1 mol/l) of hydrochloric acid (HCl).
The hard water shall be freshly prepared under aseptic conditions and used within 12 h. NOTE When preparing the product test solutions (5.4.2), the addition of the product to the hard water produces different final water hardness in each test tube. In any case, the final hardness expressed as calcium carbonate (CaCO3) is lower than 375 mg/l in the test tube. SIST EN 13727:2012
EN 13727:2012 (E) 11 5.2.2.8 Interfering substance 5.2.2.8.1 General The interfering substance shall be chosen according to the conditions of use laid down for the product.
The interfering substance shall be sterile and prepared at 10 times its final concentration in the test (50 times in the case of the modified method, 5.2.2.8.4). The ionic composition (e.g. pH, calcium and/or magnesium hardness) and chemical composition (e.g. mineral substances, protein, carbohydrates, lipids and detergents) shall be defined. NOTE The term “interfering substance” is used even if it contains more than one substance. 5.2.2.8.2 Clean conditions (bovine albumin solution – low concentration) Dissolve 0,30 g of bovine albumin fraction V (suitable for microbiological purposes) in 100 ml of diluent (5.2.2.4). Sterilize by membrane filtration (5.3.2.7), keep in a refrigerator (5.3.2.8) and use within one month. The final concentration of the bovine albumin in the test procedure (5.5) shall be 0,3 g/l ; 5.2.2.8.3 Dirty conditions (Mixture of bovine albumin solution – high concentration with sheep erythrocytes) Dissolve 3,00 g of bovine albumin fraction V (suitable for microbiological purposes) in 97 ml of diluent (5.2.2.4). Sterilize by membrane filtration (5.3.2.7). Prepare at least 8,0 ml fresh defibrinated sheep blood (5.2.2.9). Centrifuge the erythrocytes at 800 gN for 10 min (5.3.2.13). After discarding the supernatant, resuspend erythrocytes in diluent (5.2.2.4). Repeat this procedure at least 3 times, until the supernatant is colourless.
Resuspend 3 ml of the packed sheep erythrocytes in the 97 ml of sterilized bovine albumin solution (see above). To avoid later contamination this mixture should be split in portions probably needed per day and kept in separate containers for a maximum of 7 days in a refrigerator (5.3.2.8). The final concentration of bovine albumin and sheep erythrocytes in the test procedure (5.5) shall be 3 g/l and 3 ml/l respectively. 5.2.2.8.4 Clean and dirty conditions for the modified method for ready-to-use products (5.5.4) Follow the procedures for preparation according to 5.2.2.8.2 and 5.2.2.8.3, but prepare the interfering substance in fivefold higher concentrations, for the dirty conditions maximum 50 ml to avoid problems with the filtration. a) Clean conditions (5.2.2.8.2) – dissolve 1,50 g bovine albumin (instead of 0,3 g) in 100 ml of diluent; b) Dirty conditions (5.2.2.8.3) – dissolve 7,5 g bovine albumin (instead of 1,5 g) in 42,5 ml of diluent (instead of 48,5 ml). Prepare at least 20 ml (instead of 4,0 ml) sheep blood. Resuspend 7,5 ml (instead of 1,5 ml) of the packed sheep erythrocytes in 42,5 ml of sterilized bovine albumin solution to obtain 50 ml. SIST EN 13727:2012
EN 13727:2012 (E) 12 5.2.2.9 Defibrinated sheep blood The defibrinated sheep blood should be sterile (aseptic blood-letting and preparation), pooled from more than one sheep and can be acquired from a commercial supplier. 5.3 Apparatus and glassware 5.3.1 General Sterilize all glassware and parts of the apparatus that will come into contact with the culture media and reagents or the sample, except those which are supplied sterile, by one of the following methods: a) by moist heat, in the autoclave [5.3.2.1 a)]; b) by dry heat, in the hot air oven [5.3.2.1 b)]. 5.3.2 Usual microbiological laboratory equipment2) and, in particular, the following: 5.3.2.1 Apparatus for sterilization (moist and dry heat) a) For moist heat sterilization, an autoclave capable of being maintained at (30121+) °C for a minimum holding time of 15 min;
b) for dry heat sterilization, a hot air oven capable of being maintained at (50180+) °C for a minimum holding time of 30 min, at (170 50+) °C for a minimum holding time of 1 h or at (50160+) °C for a minimum holding time of 2 h. 5.3.2.2 Water baths, capable of being controlled at 20 °C ± 1 °C, at 45 °C ± 1 °C (to maint
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