ISO 19984-2:2025

International
Standard
ISO 19984-2
Second edition
Rubber and rubber products —
2025-06
Determination of biobased
content —
Part 2:
Biobased carbon content
Élastomères et produits à base d'élastomères — Détermination
de la teneur en composés biosourcés —
Partie 2: Teneur en carbone biosourcé
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, and abbreviated terms . 2
3.1 Terms and definitions .2
3.2 Abbreviated terms .2
4 Principle . 2
5 Sampling . 3
6 Measuring method of biobased carbon content by determination of C content . 3
6.1 General .3
6.2 Sample preparation and two methods to determine C concentration . .4
6.3 Calculation of the biobased carbon content .4
6.3.1 General .4
6.3.2 Correction factor .4
TC
6.3.3 Calculation of χχ , the biobased carbon content by Method A (AMS) .
B
TC
6.3.4 Calculation of χχ , the biobased carbon content by Method B (LSC) .
B
6.3.5 Examples .6
7 Precision . 6
8 Test report . 6
Annex A (normative) Method A — Determination by accelerator mass spectrometry (AMS) . 7
Annex B (normative) Method B — Determination by liquid scintillation counter (LSC) .10
Annex C (informative) Examples of the determination of biobased carbon content .13
Annex D (informative) Determination of the biobased carbon content of a tyre . 14
Annex E (informative) Precision results from an interlaboratory test programme . 17
Bibliography . 19

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee
SC 2, Testing and analysis.
A list of all parts in the ISO 19984 series can be found on the ISO website.
This second edition cancels and replaces the first edition (ISO 19984-2:2017), which has been technically
revised.
The main changes are as follows:
— REF values after 2020 have been added in Table 2;
— several bibliographic entries have been added.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
The use of biomass materials in rubber compounds helps to decrease the rubber industry’s dependence
on fossil resources. It is also expected to lead to a reduction of carbon dioxide emission, reducing global
warming and promoting a sustainable global environment.
In the ISO 19984 series, biomass is the term used for the biological material from living or recently living
organisms such as wood and agricultural waste materials.
Industrial scale biomass is now readily being grown from numerous types of plant sources and a variety of
tree species. Biomass also includes plant or animal matter used for the production of fibres or chemicals. It
can also include biodegradable wastes. Biomass excludes organic materials which have been transformed
by geological processes into substances, such as petroleum or coal. Although fossil fuels have their origin in
ancient biomass, they are not considered biomass by the generally accepted definition because they contain
carbon that has been “out” of the modern carbon cycle.
The composition of biomass is mainly carbon, hydrogen and oxygen. Nitrogen and small quantities of other
elements can also be found.
The ISO 19984 series specifies methods for the determination of the biobased content of rubber and rubber
products. The results will give manufacturers and users a quantitative indication of their contribution to the
preservation of the environment.
ISO 19984-1 specifies how to categorize constituents of rubber and rubber products and how to calculate
the biobased content using the compound formulation and the chemical structure of each constituent.
ISO 19984-2 specifies how to determine the biobased carbon content by radio chemical analyses, i.e.
determination of C. It can be obtained from the fraction of carbon atoms derived from biomass against
the whole amount of carbon atoms in the rubber or rubber products. The methods specified in ISO 19984-2
allow consumers to determine the biobased carbon content even when the formulation of the rubber is
unavailable.
ISO 19984-3 specifies how to separate rubber compounds into constituents, how to obtain each constituent's
composition ratio and how to determine the biobased carbon content of each constituent by chemical
analyses. Thus, the biobased mass content for each constituent can be derived and the biobased mass content
for the whole rubber can be obtained by summing up all the constituent values.

v
International Standard ISO 19984-2:2025(en)
Rubber and rubber products — Determination of biobased
content —
Part 2:
Biobased carbon content
WARNING 1 — 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 determine the applicability of any other restrictions.
WARNING 2 — Certain procedures specified in this document can involve the use or generation
of substances, or the generation of waste, that can constitute a local environmental hazard. It is the
responsibility of the user to refer to appropriate documentation on safe handling and disposal after use.
1 Scope
This document specifies measuring methods for the determination of biobased carbon contents in rubber
and rubber products, including polyurethanes. The methods focus on carbon atoms in rubber or rubber
products, and determine whether the carbon-containing component is biobased or not, judging from the
concentration of C, radiocarbon isotope.
This document applies to rubber and rubber products such as raw materials, materials and final products.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 123, Rubber latex — Sampling
ISO 124, Latex, rubber — Determination of total solids content
ISO 1382, Rubber — Vocabulary
ISO 1795, Rubber, raw natural and raw synthetic — Sampling and further preparative procedures
ISO 1928, Coal and coke — Determination of gross calorific value
ISO 4661-2, Rubber, vulcanized — Preparation of samples and test pieces — Part 2: Chemical tests
ISO 15528, Paints, varnishes and raw materials for paints and varnishes — Sampling
ISO 19242, Rubber — Determination of total sulfur content by ion chromatography
ISO 19984-1, Rubber and rubber products — Determination of biobased content — Part 1: General principles
and calculation methods using the formulation of the rubber compound

3 Terms, definitions, and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1382 and ISO 19984-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1.1
percent modern carbon
pMC
normalized and standardized value for the amount of the C isotope in a sample, calculated relative to the
1)
standardized and normalized C isotope amount of oxalic acid standard reference material, SRM 4990c
Note 1 to entry: The reference value of 100 % biobased carbon is given in Table 2.
3.1.2
C activity
relative concentration of radiocarbon C expressed as a counting of β-irradiation from the decayed
radiocarbon atoms per minute
Note 1 to entry: The unit of C activity is “dpm” (decay per minute).
14 14
No
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