ISO 20851:2017

Synthetic rubber latex — Examination for microorganisms

ISO 20851:2017 specifies the method to examine the presence and approximate count of viable aerobic and facultative anaerobic microorganisms in synthetic rubber latices. Identification of the microorganisms is outside the scope of this document.

Latex de caoutchouc synthétique — Examen des micro-organismes

General Information

• Status: Published
• Publication Date: 07-Aug-2017
• ICS: 83.040.10 - Latex and raw rubber
• Technical Committee: ISO/TC 45/SC 3 - Raw materials (including latex) for use in the rubber industry
• Drafting Committee: ISO/TC 45/SC 3/WG 2 - Latex
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 01-Jul-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20851
First edition
2017-07
Synthetic rubber latex — Examination
for microorganisms
Latex de caoutchouc synthétique — Examen des micro-organismes
Reference number
ISO 20851:2017(E)
©
ISO 2017

---------------------- Page: 1 ----------------------
ISO 20851:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 20851:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagent . 2
6 Apparatus . 2
7 Sampling . 2
8 Procedure. 2
9 Examination . 3
9.1 Examination of the microbial count (CFU/ml) . 3
9.2 Interpretation . 3
10 Disposal of the used slides and equipment . 3
11 Test report . 3
Annex A (informative) Example of a model chart . 4
Annex B (informative) Interpretation of the microbial count . 5
© ISO 2017 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 20851:2017(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member 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 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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html
This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products,
Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry.
iv © ISO 2017 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 20851:2017(E)

Introduction
Synthetic latices are susceptible to post-production contamination with microorganisms during storage
and shipment. Unless precautions are taken, such as maintenance of a high pH, the addition of biocide
and inspection and cleaning of tanks, these organisms may proliferate, ultimately producing unpleasant
odours and changes in the chemical and physical properties of the latex. It is highly desirable to be able
to detect the presence of significant microorganisms before such changes develop.
This document replaces ISO 9252:1989, Synthetic rubber latex – Microbiological examination, which
was withdrawn due to its obsolescence and complicated testing procedures. This document provides
a far more simplified method for the purpose of microbiological examination, employing a ready-made
medium slide as reagent.
© ISO 2017 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 20851:2017(E)
Synthetic rubber latex — Examination for microorganisms
WARNING 1 — Persons using this document should be familiar with normal laboratory practice.
This document does not purport to address all of the safety problems, if any, associated with its
use. It is the responsibility of the user to establish appropriate safety and health practices and to
ensure compliance with any national regulatory conditions.
WARNING 2 — Certain procedures
...