ISO 20851:2017

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

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ISO 20851:2017(E)

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© ISO 2017, Published in Switzerland
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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
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ISO 20851:2017(E)

Foreword
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electrotechnical standardization.
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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.
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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was withdrawn due to its obsolescence and complicated testing procedures.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.
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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
...