ISO INTERNATIONAL STANDARD 846 Third edition 2019-03 Plastics Evaluation of the action of microorganisms Plastiques - Evaluation de I'action des micro-organismes Reference number IS0 846:2019(E) Tso @IS02019 IS0 846:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ IS0 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland i @ IS0 2019 - All rights reserved IS0 846:2019(E) Contents Page Foreword ..V Introduction. ..vii 1 Scope. 2 Normative references 3 Terms and definitions ..1 4 Principle .2 4.1 General .2 4.2 Resistance to fungi. .2 4.2.1 Method A: Fungal-growth test. .2 .2 4.2.2 Method B: Determination of fungistatic effects 4.3 Method C: Resistance to bacteria. 3 4.4 Method D: Resistance to microbially active soil (soil-burial test) .3 4.5 Choice of properties for assessment of biodeterioration .3 5 Apparatus and materials. .3 5.1 Foralltests .3 5.2 For tests with fung.. .4 5.3 For tests with bacteria ..6 5.4 For soil-burial tests. .6 Test specimens. .7 6 6.1 Shape and dimensions .1 6.2 Specimen test series and numbers in each test series. .7 6.2.1 Specimen test series. .7 6.2.2 Numbers in each test series ..8 7 Preparation of specimens .8 7.1 Cleaning. ..8 7.2 Labelling and storage 7.3 Conditioning and weighing ..8 Procedures. 8 .9 8.1 Test temperature .9 8.2 Test methods. 9 8.2.1 General. .9 8.2.2 Fungal-growth test (method A) .9 8.2.3 Determination of fungistatic effect (method B) ..11 8.2.4 Procedure with bacteria (method C) ..12 8.2.5 Soil-burial test (method D) ..13 9 Assessment ..14 9.1 Assessment of fungal growth on the specimens by visual examination (methods A, B and D). ..14 9.2 Evaluation of the test specimens for the determination of changes in mass and/or in other physical properties .15 9.2.1 Cleaning. .. 15 9.2.2 Change in mass .15 9.2.3 Determination of changes in other physical properties .16 10 Expression of results .16 10.1 General .16 10.2 Visual assessment .16 10.3 Change in mass. ..16 10.4 Changes in other physical properties. ..16 11 Accuracy of the measurements .17 @ IS0 2019 - All rights reserved iii