1、BRITISH STANDARD BS EN ISO 846:1997 Plastics Evaluation of the action of microorganisms The European Standard EN ISO 846:1997 has the status of a British Standard ICS 07.100.99; 83.080.01BSEN ISO 846:1997 This British Standard, having been prepared under the directionof the Sector Board forMaterials
2、 and Chemicals, waspublished under the authorityof the Standards Boardand comes into effect on 15 September 1997 BSI 10-1999 ISBN 0 580 27880 8 National foreword This British Standard is the English language version of EN ISO846:1997. It is identical with ISO846:1997. The UK participation in its pre
3、paration was entrusted to Technical Committee PRI/21, Testing of plastics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests inform
4、ed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which
5、 lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence
6、Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itsel
7、f confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN ISO title page, page 2, the ISO title page, pages ii to iv, pages1 to15 and a back cover. This standard has been updated (see copyright date) and may have had
8、amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSEN ISO 846:1997 BSI 10-1999 i Contents Page National foreword Inside front cover Foreword 2 Foreword iii Text of ISO 846 1ii blankEUROPEAN STA
9、NDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 846 June 1997 ICS 07.100.01; 83.080.01 Descriptors: See ISO document English version Plastics Evaluation of the action of microorganisms (ISO 846:1997) Plastiques Evaluation de laction des micro-organismes (ISO846:1997) This European Standard was approved
10、 by CEN on1997-05-15. 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 standard
11、s may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist 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
12、Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKing
13、dom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO846:1997E
14、ENISO 846:1997 BSI 10-1999 2 Foreword The text of the International Standard ISO846:1997has been prepared by Technical Committee ISO/TC61 “Plastics” in collaboration with Technical Committee CEN/TC249 “Plastics”, the secretariat of which is held by IBN. This European Standard shall be given the stat
15、us of a national standard, either by publication of an identical text or by endorsement, at the latest by December1997, and conflicting national standards shall be withdrawn at the latest by December 1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
16、 following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom. Endorsement notice The text of the Int
17、ernational Standard ISO846:1997was approved by CEN as a European Standard without any modification.EN ISO846:1997 ii BSI 10-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Principle 2 5 Apparatus and materials 3 6 Test specimens 5 7 Preparation of
18、specimens 5 8 Procedures 5 9 Assessment 9 10 Expression of results 10 11 Accuracy of the measurements 11 12 Test report 11 13 Bibliography 12 Annex A (normative) Determination of the water content and water-holding capacity of a soil 13 Annex B (informative) Precision 14 Annex C (informative) Inform
19、ation on test fungi 15 Figure 1 Arrangement of test specimens in the soil in soil-burial tests (cross-section) 9 Table 1 3 Table 2 3 Table 3 Summary of test methods 6 Table 4 Assessment of fungal growth 9 Table 5 Interpretation of results 10 Descriptors: Plastics, plastics products, pest resistance,
20、 microorganisms, tests, pest resistance tests, physicochemical tests, estimation, deterioration, biodeterioration, specimen preparation.EN ISO846:1997 BSI 10-1999 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member
21、bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental
22、and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member
23、bodies for voting. Publication as an International Standard requires approval by at least75%of the member bodies casting a vote. International Standard ISO846was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC6, Ageing, chemical and environmental resistance. This second edition c
24、ancels and replaces the first edition (ISO846:1978), which has been technically revised. The Plastics Project Group of the IBRG (International Biodeterioration Research Group) carried out several interlaboratory tests between1984and1990, using the1978edition of this standard, with the aim of checkin
25、g the reproducibility of the test results. The experience gained from these tests has been incorporated in the present edition. In addition, a soil-burial test method has been included in subclause 8.5, based on a specification the Eidgenssische Materialprfungsanstalt in St. Gallen, Switzerland. Ann
26、ex A forms an integral part of this International Standard. Annex B and Annex C are for information only.iv blankEN ISO846:1997 BSI 10-1999 1 Introduction Under certain climatic and environmental conditions, microorganisms may settle on and colonize the surface of plastics or plastics products. Thei
27、r presence and/or their metabolic products may not only damage the plastic itself, but may also affect the serviceability of building materials and systems containing plastic parts. The tests and test conditions specified in this International Standard are empirical and cover most- but not all- pote
28、ntial applications. For specific applications and for long-term tests, procedures should be agreed upon which reflect performance under actual conditions. The actions of microorganisms on plastics are influenced by two different processes: a) direct action: the deterioration of plastics which serve
29、as a nutritive substance for the growth of the microorganisms; b) indirect action: the influence of metabolic products of the microorganisms, e.g.discolouration or further deterioration. This International Standard deals with both of these two processes, as well as their combined action. WARNING Han
30、dling and manipulation of microorganisms which are potentially hazardous requires a high degree of technical competence and may be subject to current national legislation and regulations. Only personnel trained in microbiological techniques should carry out such tests. Codes of practice for disinfec
31、tion, sterilization and personal hygiene must be strictly observed. It is recommended that workers consult IEC68-2-10:1988, Appendix A “Danger to personnel”, and ISO7218:1996, Microbiology of food and animal feeding stuffs General rules for microbiological examinations. 1 Scope This International St
32、andard specifies methods for determining the deterioration of plastics due to the action of fungi and bacteria and soil microorganisms. The aim is not to determine the biodegradability of plastics. The type and extent of deterioration may be determined by a) visual examination and/or b) changes in m
33、ass and/or c) changes in other physical properties. The tests are applicable to all articles made of plastic that have an even surface and that can thus be easily cleaned. The exceptions are porous materials, such as plastic foams. This International Standard uses the same test fungi as IEC68-2-10.
34、The IEC method, which uses so-called “assembled specimens”, calls for inoculation of the specimens with a spore suspension, incubation of the inoculated specimens and assessment of the fungal growth as well as any physical attack on the specimens. The volume of testing and the test strains used will
35、 depend on the application envisaged for the plastic. These parameters should therefore be agreed upon before the tests and should be stated in the test report. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this Inte
36、rnational Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below
37、. Members of IEC and ISO maintain registers of currently valid International Standards. ISO291:, Plastics Standard atmospheres for conditioning and testing 1) . IEC68-2-10:1988, Basic environmental testing procedures Part2: Tests Test J and guidance: Mould growth. 3 Definitions For the purposes of t
38、his International Standard, the following definitions apply: 3.1 biodeterioration a change in the chemical or physical properties of a material due to the action of a microorganism 3.2 fungistatic effect the antimycotic effect of an antimicrobial treatment which prevents a given material from being
39、overgrown by fungi under moist conditions 1) To be published. (Revision of ISO291:1977)EN ISO846:1997 2 BSI 10-1999 3.3 biodegradation the term “biodegradation” is being discussed by TC61/SC5/WG22, Biodegradability, and the official definition will be included here when it is available 4 Principle 4
40、.1 The test involves exposing test specimens of plastic to the action of selected test strains of fungi and bacteria (or, in the case of the soil-burial test, to microbially active soil) for specified or agreed periods of time under specified conditions of temperature and humidity. At the end of the
41、 exposure, the test specimens are assessed before and/or after cleaning by visual examination and/or any change in mass or other physical properties is determined. The results obtained with the specimens exposed to biological attack (batch I) are compared with those obtained from untreated specimens
42、 (batch 0) or sterile specimens (batch S) kept under the same conditions. 4.2 Short descriptions of the test methods used to determine the resistance of plastics to fungi (methodA) or the fungistatic effects (methods B and B), resistance to bacteria (method C) and resistance to soil microorganisms (
43、method D) are given below. 4.2.1 Resistance to fungi 4.2.1.1 Method A: Fungal-growth test Test specimens are exposed to a mixed suspension of fungus spores in the presence of an incomplete nutritive medium (without a carbon source). The fungi can only grow at the expense of the material. If the spec
44、imens contain no nutritive component, the fungi cannot develop mycelia and there is no deterioration of the plastic. Method A is suitable for the assessment of the inherent resistance of plastics to fungal attack in the absence of other organic matter. It is recommended that, when method A is carrie
45、d out, methods B and B are also carried out to assist in the interpretation of the results. 4.2.1.2 Methods B and B: Determination of fungistatic effects Test specimens are exposed to a mixed suspension of fungus spores in the presence of a complete medium, i.e. with a carbon source. Even if the pla
46、stic does not contain any nutritive elements, the fungi can grow over the specimens and their metabolic products can attack the material. Any inhibition of the growth either on the plastic or in the growth medium (zone of inhibition) shows fungistatic activity of the plastic or the presence of a fun
47、gicidal treatment. In method B, the specimens are not placed on the nutritive medium until it is completely overgrown. Methods B and B are used when surface contamination is expected. In order to save time, and for a better understanding of the phenomenon, it is recommended that the two methods are
48、carried out simultaneously. 4.2.2 Method C: Resistance to bacteria The action of bacteria on test specimens is assessed using an incomplete medium. If there is no growth in the agar round the specimen, then the specimen does not contain any nutritive components. 4.2.3 Method D: Resistance to microbi
49、ally active soil (soil-burial test) Test specimens are completely buried in natural soil with a known water-holding capacity and a specified moisture content (see Annex A). The soil-burial test has been included in this International Standard because many plastics are used in permanent contact with soil and exposed to high humidities. 4.3 Choice of properties for assessment of biodeterioration The choice of the properties to be determined depends on the aim of the test. A visual assessment of biological attack should preferably alw
