Bio-based products - Overview of methods to determine the bio-based content

CEN/TR 16721 gives an overview of methods which can be used for the determination of the bio-based content of solid, liquid and gaseous products. It describes more specifically: a) a method using the radiocarbon analysis and elemental analysis: this method is based on a statement and a verification of the composition of the products; b) methods based on measurement of stable isotopic ratio; and c) a method based on the material balance. This Technical Report gives guidance on the applicability of the different methods. This Technical Report also gives recommendations for the further development of European Standards for the determination of the bio-based content.

Biobasierte Produkte - Überblick über verfügbare und mögliche Methoden und Techniken zur Bestimmung des gesamten biobasierten Gehaltes von Produkten

Dieser Technische Bericht gibt einen Überblick über Verfahren, die zur Bestimmung des biobasierten Gehalts von festen, flüssigen und gasförmigen Produkten angewendet werden können. Insbesondere wird Folgendes beschrieben:
a)   ein Verfahren unter Anwendung der Radiokarbonanalyse und der Elementaranalyse: dieses Verfahren beruht auf einer Angabe und einer Verifizierung der Zusammensetzung der Produkte;
b)   Verfahren auf der Grundlage der Messung stabiler Isotopenverhältnisse; und
c)   ein Verfahren auf der Grundlage der Materialbilanz.
Dieser Technische Bericht gibt eine Orientierungshilfe zur Anwendbarkeit der verschiedenen Verfahren.
Dieser Technische Bericht enthält außerdem Empfehlungen zur Weiterentwicklung von Europäischen Normen zur Bestimmung des biobasierten Gehalts.

Produits biosourcés - Vue d'ensemble des méthodes pour déterminer la teneur biosourcée

Le présent Rapport technique donne une vue d’ensemble des méthodes qui peuvent être utilisées pour déterminer la teneur biosourcée des produits solides, liquides et gazeux. Il décrit plus particulièrement :
a)   une méthode utilisant l’analyse du radiocarbone et l’analyse élémentaire : cette méthode repose sur une déclaration et une vérification de la composition des produits ;
b)   des méthodes reposant sur la mesure des rapports d’isotopes stables ; et
c)   une méthode reposant sur le bilan matière.
Le présent Rapport technique donne des lignes directrices sur l’applicabilité des différentes méthodes.
Il fournit également des recommandations sur l’élaboration future de Normes européennes relatives à la détermination de la teneur biosourcée.

Bioizdelki - Pregled metod za določanje biodeleža v izdelkih

Tehnično poročilo CEN/TR 16721 podaja pregled metod, ki jih je mogoče uporabljati za določanje biodeleža v trdnih, tekočih in plinastih izdelkih. Podrobneje opisuje: a) metodo, ki uporablja analizo z ogljikom in analizo elementov: ta metoda temelji na izjavi in preverjanju sestave izdelkov; b) metode, ki temeljijo na merjenju stabilnega izotopnega deleža; in c) metodo, ki temelji na ravnovesju materiala. To tehnično poročilo podaja smernice o uporabi različnih metod. To tehnično poročilo podaja tudi priporočila za dodatni razvoj evropskih standardov za določanje biodeleža.

General Information

Status
Published
Public Enquiry End Date
30-May-2014
Publication Date
18-Aug-2014
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
18-Aug-2014
Due Date
23-Oct-2014
Completion Date
19-Aug-2014

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SLOVENSKI STANDARD
SIST-TP CEN/TR 16721:2014
01-oktober-2014
%LRL]GHONL3UHJOHGPHWRG]DGRORþDQMHELRGHOHåDYL]GHONLK
Bio-based products - Overview of methods to determine the bio-based content
Biobasierte Produkte - Überblick über verfügbare und mögliche Methoden und
Techniken zur Bestimmung des gesamten biobasierten Gehaltes von Produkten
Produits biosourcés - Vue d'ensemble des méthodes pour déterminer la teneur
biosourcée
Ta slovenski standard je istoveten z: CEN/TR 16721:2014
ICS:
13.020.60 Življenjski ciklusi izdelkov Product life-cycles
71.100.01 Izdelki kemijske industrije na Products of the chemical
splošno industry in general
SIST-TP CEN/TR 16721:2014 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CEN/TR 16721:2014
TECHNICAL REPORT
CEN/TR 16721
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
August 2014
ICS 13.020.60
English Version
Bio-based products - Overview of methods to determine the bio-
based content

Produits biosourcés - Vue d'ensemble des méthodes pour Biobasierte Produkte - Überblick über verfügbare und

déterminer la teneur biosourcée mögliche Methoden und Techniken zur Bestimmung des

gesamten biobasierten Gehaltes von Produkten

This Technical Report was approved by CEN on 21 July 2014. It has been drawn up by the Technical Committee CEN/TC 411.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United

Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16721:2014 E

worldwide for CEN national Members.
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Contents Page

Foreword ..............................................................................................................................................................3

Introduction .........................................................................................................................................................4

1 Scope ......................................................................................................................................................5

2 Terms and definitions ...........................................................................................................................5

3 Method using the radiocarbon analysis and elemental analysis .....................................................5

3.1 Background ............................................................................................................................................5

3.2 Principle ..................................................................................................................................................6

3.3 Basic rules ..............................................................................................................................................6

3.3.1 Oxygen, hydrogen and nitrogen elements ..........................................................................................6

3.3.2 Chemical reactions ................................................................................................................................6

3.3.3 Natural products ....................................................................................................................................7

3.4 Test methods ..........................................................................................................................................7

3.5 Products obtained by chemical synthesis (Group 1).........................................................................7

3.5.1 General ....................................................................................................................................................7

3.5.2 Validation criteria ...................................................................................................................................8

3.6 Formulated products (Group 2) ............................................................................................................9

3.6.1 General ....................................................................................................................................................9

3.6.2 Calculation of the bio-based content of a sample ..............................................................................9

3.6.3 Calculation of the bio-based carbon content of a sample ............................................................. 10

3.6.4 Assessment of deviations of measured 14C values from theoretical values .............................. 11

4 Methods based on measurement of stable isotopic ratio .............................................................. 11

4.1 General ................................................................................................................................................. 11

4.1.1 Introduction ......................................................................................................................................... 11

4.1.2 Material and Methods ......................................................................................................................... 12

13 12

4.2 C/ C isotope ratio ............................................................................................................................ 14

18 16

4.3 O/ O isotope ratio ........................................................................................................................... 14

4.3.1 Isotopic measurement of water ......................................................................................................... 14

4.3.2 Isotopic measurements of organic samples .................................................................................... 14

2 1

4.4 H/ H isotope ratio............................................................................................................................... 15

15 14

4.5 N/ N Isotope ratio ............................................................................................................................ 15

4.6 Isotopes S ............................................................................................................................................ 15

4.7 Multi-isotopic determinations ............................................................................................................ 15

5 Method based on material balance ................................................................................................... 15

5.1 General ................................................................................................................................................. 15

5.2 Principle ............................................................................................................................................... 16

5.3 Examples ............................................................................................................................................. 16

5.3.1 Paint formulation ................................................................................................................................ 16

5.3.2 Flexible insulation panel made from wood fibres ........................................................................... 17

6 Applicability of the different methods .............................................................................................. 17

7 Recommendations .............................................................................................................................. 18

Annex A (informative) Isotope ratio tables .................................................................................................. 19

Bibliography ..................................................................................................................................................... 23

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Foreword

This document (CEN/TR 16721:2014) has been prepared by Technical Committee CEN/TC 411 “Bio-based

products”, the secretariat of which is held by NEN.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. CEN shall not be held responsible for identifying any or all such patent rights.

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Introduction

Bio-based products from forestry and agriculture have a long history of application, such as paper, board and

various chemicals and materials. The last decades have seen the emergence of new bio-based products in

the market. Some of the reasons for the increased interest lie in the bio-based products’ benefits in relation to

the depletion of fossil resources and climate change. Bio-based products may also provide additional product

functionalities. This has triggered a wave of innovation with the development of knowledge and technologies

allowing new transformation processes and product development.

Acknowledging the need for common standards for bio-based products, the European Commission issued

mandate M/492 , resulting in a series of standards developed by CEN/TC 411, with a focus on bio-based

products other than food, feed and biomass for energy applications.

The standards of CEN/TC 411 "Bio-based products" provide a common basis on the following aspects:

− Common terminology;
− Bio-based content determination;
− Life Cycle Assessment (LCA);
− Sustainability aspects;
− Declaration tools.

It is important to understand what the term bio-based product covers and how it is being used. The term "bio-

based" means "derived from biomass". Bio-based products (bottles, insulation materials, wood and wood

products, paper, solvents, chemical intermediates, composite materials, et cetera.) are products which are

wholly or partly derived from biomass. It is essential to characterize the amount of biomass contained in the

product by for instance its bio-based content or bio-based carbon content.

The bio-based content of a product does not provide information on its environmental impact or sustainability,

which may be assessed through LCA and sustainability criteria. In addition, transparent and unambiguous

communication within bio-based value chains is facilitated by a harmonized framework for certification and

declaration.

The purpose of this Technical Report is provide an overview of methods for the determination of the bio-based

content of solid, liquid and gaseous products.

The ability to determine the bio-based content of a product is an obvious prerequisite for developing the

market for bio-based products. Currently, the bio-based content is usually derived from the determination of

the bio-based carbon content by means of C measurement (as described in ASTM D6866-12 [1]).This

methodology is used because C is measurable.

However, results based on the C methodology are expressed as a fraction of bio-based carbon on the total

(organic) carbon content of the sample. In some cases the bio-based content of a product can differ

substantially from the bio-based carbon content. For example, for products in which a fraction of the raw

materials has been replaced by bio-based materials/constituents containing other elements such as oxygen,

nitrogen or hydrogen (e.g. carbohydrate-based products), the bio-based carbon content may be substantially

lower than the fraction of the product that is derived from biomass. This Technical Report describes three

different methodologies to determine the bio-based content in a product and proposes the development of

standards.

It should be noted that the quantification of the bio-based content is not a measure of sustainability of a

bio-based product.

A Mandate is a standardization task embedded in European trade laws. M/492 Mandate is addressed to the European

Standardization bodies, CEN, CENELEC and ETSI, for the development of horizontal European Standards for bio-based

products.
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1 Scope

This Technical Report gives an overview of methods which can be used for the determination of the bio-based

content of solid, liquid and gaseous products. It describes more specifically:

a) a method using the radiocarbon analysis and elemental analysis: this method is based on a statement

and a verification of the composition of the products;
b) methods based on measurement of stable isotopic ratio; and
c) a method based on the material balance.

This Technical Report gives guidance on the applicability of the different methods.

This Technical Report also gives recommendations for the further development of European Standards for the

determination of the bio-based content.
2 Terms and definitions

For the purposes of this document, the terms and definitions given in FprEN 16575:2014 [2] and the following

apply.
2.1
formulated product
product obtained by mixing of different constituents
2.2
material balance

comparison of physical quantities of inputs, outputs and inventory changes in a quantity centre over a

specified time period
[SOURCE: ISO 14051:2011, 3.1]
3 Method using the radiocarbon analysis and elemental analysis
3.1 Background

Element carbon, C, has an isotope, C, which allows for a clear distinction between carbon based substances

derived from biomass and carbon based substances from fossil sources. The C present in chemicals

originates from recent atmospheric CO . Due to its radioactive decay, it is almost absent from fossil products

older than 20 000 years to 30 000 years. The C content may thus be considered as a tracer of chemicals

recently synthesized from atmospheric CO and particularly of recently produced products.

The approach based on isotopic measurements to determine the bio-based content of a sample can be used

for carbon but not for other elements, such as oxygen, nitrogen or hydrogen.

However the content of each element can be determined by an elemental analysis which leads to the total

content of each element, but does not differentiate the elements according to their origin from bio-based

resources or fossil resources. Therefore, the combination of the C content determination and an elemental

analysis does not give the bio-based content of a sample. To circumvent this difficulty, the method as given

in 3.2 is proposed.

NOTE The bio-based content of a product can be derived from the bio-based carbon content if the composition of the

biomass used is unchanged. Even for derivatives the bio-based carbon content can be used if the chemistry behind the

conversion is well known and constant.
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3.2 Principle

NOTE 1 This method is under development and at the end of experiment phase the results will be taken into account

when drafting the European Standard dealing with this method.

This method, supported by rules described in 3.3, consists of the statement of the bio-based content and of

the elemental content of the sample obtained by calculation. This statement is validated by means of a

comparison with the same kind of data resulting from the C analysis and the elemental analysis of the

sample.

NOTE 2 The "statement" in the sense of this document is not to be confused with the "declaration" of the bio-based

content, based on the results of this method.

Products can be classified into two groups, chemicals and formulated products depending on the type of

analyses to be carried out:

a) Group 1: products obtained by chemical synthesis. A representative sample is analysed on the following

criteria: C content determination and elemental analysis of carbon, hydrogen, oxygen and/or nitrogen. If

other elements are present, they may also be analysed. The validation process uses common rules of

stoichiometry for these products. See 3.5;

b) Group 2: formulated products. A representative sample is analysed with the C method only, if the bio-

based content of the constituents (Group 1) of the product are analysed according to this method. The

validation process uses a calculation by mass for these products. See 3.6.

NOTE 3 Since Group 2 formulated products can be made from several constituents, even in a large number, the

complete method described for Group 1 may be difficult to implement. This is the reason why a simplified method was

developed for the formulated products of Group 2.
3.3 Basic rules
3.3.1 Oxygen, hydrogen and nitrogen elements

As it is not possible to make a distinction between bio-based and non-bio-based elements such as oxygen,

hydrogen or nitrogen, for the application of this method in this Technical Report, the following convention

applies:

If oxygen (O) and/or hydrogen (H) and/or nitrogen (N) element(s) is(are) bound to a biomass carbon structure,

it(they) is(are) considered to be part(s) of the bio-based content.
3.3.2 Chemical reactions

For products/constituents of products obtained by chemical synthesis, the following guidance is proposed:

a) in case that the chemical reaction occurs without release of by-products:

1) if the reactants are exclusively derived from biomass, the bio-based content of the

product/constituent of the product is 100 %; if none of the reactants is derived from biomass, the bio-

based content of the product/constituent of the product is 0 %;

2) if the reactants are derived from both biomass and fossil resource, the final product has a bio-based

content proportional to the bio-based content of each reactant;

b) in case that the chemical reaction leads to the release of a molecule which is not part of the main product,

the allocation of the main elements of the reactants follows the basic chemical rules.

EXAMPLE Esterification leads to the release of a water molecule, in which the oxygen will be considered as coming

from the acid according to the usual chemical rules.
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3.3.3 Natural products

The bio-based carbon content and the bio-based content of natural products [e.g. wood (including pulp), flax,

hemp, bamboo] are each equal to 100 %. Therefore, it is not necessary to determine these contents by

analytical methods.
3.4 Test methods

The bio-based carbon content of a sample can be determined according to FprCEN/TS 16640 [3], Method C

(AMS). Alternatively, the bio-based carbon content can be determined according to EN 15440 [4] or

CEN/TS 16137 [5], Method C, and declared according to CEN/TS 16295 [6] or ASTM D6866-12 [1] and the

results can be reported according to ASTM D7026-04 [7].

NOTE CEN/TS 16137 is applicable to plastic material and products, but the test methods can be in principle applied

to any other product.
For the elemental analysis, standard analytical methods should be used.
3.5 Products obtained by chemical synthesis (Group 1)
3.5.1 General

The statement (see 3.2) should include a detailed elemental composition of the bio-based part and the fossil

part of the product, as well as the bio-based content.

EXAMPLE 1 Bio-ethyl acetate obtained by esterification between bio-ethanol from fermentation of sugar and acetic

acid from fossil resources:
Fraction C
H O Total
% % % %
Fossil fraction (from acetic 27,3 3,4 18,2 48,9
acid)
Bio-based fraction (from 27,2 5,7 18,2 51,1
ethanol)
Total 54,5 9,1 36,4 100,0
Then, the data of the statement are compared with the results of the analysis.

If the data of the statement and the analytical results range within a defined error margin, as shown in Table 1,

the bio-based content should be validated as stated or should be rounded down according to the rules given

in 3.5.2.

The analytical results can differ from the stated values for the following reasons:

a) the composition of the product may show some variability due to its natural origin;

EXAMPLE 2 Natural fatty acids used in the production of fatty acid esters.

b) the production process may also to some extent be a cause of variability of the composition of the final

product;

c) the analytical methods are also a source of uncertainty, as follows (values pertaining to the methods):

1) ± 3 % of the measured value for the bio-based carbon content;

2) ± 0,4 % of the measured value for the total carbon, total oxygen or total nitrogen content;

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3) ± 0,2 % of the measured value for the total hydrogen content.
3.5.2 Validation criteria

The stated bio-based content of a sample can be validated by considering the bio-based carbon content

obtained from the C content determination and the analytical results of at least two more elements chosen

among total carbon, total oxygen, total hydrogen or total nitrogen.

If nitrogen and/or oxygen element(s) is(are) not present in the molecule, it(they) is(are) not taken into account.

In case of bio-ethyl acetate in 3.5.1, EXAMPLE 1, nitrogen element is not present in the molecule; therefore

nitrogen element cannot be taken into account. The validation is done by comparing the values of the

bio-based carbon content as well as the total carbon content and the hydrogen content. The total oxygen

content may also be considered instead of the total carbon content or total hydrogen content.

Three confidence levels are defined depending on the closeness between the stated values and the values

obtained by analysis. The stated bio-based content of a sample is validated if the differences between the

stated values and the values obtained by analysis comply with Table 1.
Table 1 — Decision process
Deviation between calculation and results of analysis
Confidence
Bio-based Total carbon Total hydrogen Total oxygen Total nitrogen
level
carbon content content content content content
% % % % %
1 (High) ± 3,0 ± 0,4 ± 0,2 ± 0,4 ± 0,4
2 (Medium) ± 4,5 ± 1,0 ± 0.5 ± 1,0 ± 1,0
3 (Low) ± 6,0 ± 2,0 ± 1,0 ± 2,0 ± 2,0

If at least three of the values of the differences between the stated values and the values obtained by analysis

are comprised within the uncertainties given in Table 1, then:

a) for confidence level 1, the stated value for the bio-based content is validated;

b) for confidence level 2, the stated value for the bio-based content is rounded down to the nearest "multiple

of five" percentage (e.g. 52 % is rounded down to 50 %, 57 % is rounded down to 55 %);

c) for confidence level 3, the stated value for the bio-based content is rounded down to the second nearest

"multiple of five" percentage in such a way that the difference between the stated value and the rounded

value is > 5 % (e.g. 48 % is rounded down to 40 %, 45,2 % is rounded down to 40 %).

In addition, none of the values of the differences between the stated values and the values obtained by

analysis should be higher than the values given in Table 1 for confidence level 3.

All calculations are based on results reported on a dry matter basis.
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EXAMPLE 1:
Bio-based carbon Total carbon Total hydrogen Total oxygen Bio-based content
content
% % % % %
Stated values 25,00 50,00 5,56 44,44 56
Measured values 25,86 ± 3 49,80 ± 0,4 5,68 ± 0,2 44,60 ± 0,4 -

Three values are within the maximum difference between stated value and the result of analysis defined for

confidence level 1. "56 %" is validated.
EXAMPLE 2:
Bio-based carbon Total carbon Total hydrogen Total oxygen Bio-based content
content
% % % % %
Stated values 40,8 53,0 9,0 24,2 52
Measured values 40,1 ± 4,5 52,1 ± 1,0 8,82 ± 0,5 22,46 ± 1,0 -

Three values are within the maximum difference between stated value and the result of analysis defined for

confidence level 2. "50 %" is validated.
EXAMPLE 3:
Bio-based carbon Total carbon Total hydrogen Total oxygen Bio-based content
content
% % % % %
Stated values 47,25 50,15 7,23 42,62 67
Measured values 42,2 ± 6 47,5 ± 2 7,86 ± 1 40,79 ± 2 -

Three values are within the maximum difference between stated value and the result of analysis defined for

confidence level 3. "60 %" is validated.
3.6 Formulated products (Group 2)
3.6.1 General

On the one hand, the bio-based carbon content (based on C content) of the sample should be determined

by analysis. On the other hand, the bio-based carbon content and bio-based content of the sample are

calculated from data related to the constituents and stated. It implies that the constituents of the sample have

been analysed and the statement of the bio-based content of each constituent has been validated according

to 3.5.2.
3.6.2 Calculation of the bio-based content of a sample
The bio-based content of a sample is calculated using Formula (1):
B⋅m
∑ i
i=1
(1)
B =100
Where
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B is the bio-based content of the sample expressed as a percentage of the total mass of the

sample;

B is the bio-based content of the constituent (i), expressed as a percentage of the mass of the

constituent (i);
m is the mass of the constituent (i), expressed in grams;
m is the total mass of the sample, expressed in grams;
n is the number of constituents of the sample.
3.6.3 Calculation of the bio-based carbon content of a sample
3.6.3.1 Calculation as a fraction of total carbon (TC)
The bio-based carbon content of the sample is calculated using Formula (2):
TC TC
B ⋅C ⋅m
c,i i i
TC i=1
B = 100
c,s
C ⋅m
∑ i i
i=1
(2)
Where

is the bio-based carbon content, expressed as a percentage of the total carbon content of the

c,s
sample;

is the bio-based carbon content of the constituent (i), expressed as a percentage of the total

c,i
carbon content of the constituent (i);

is the total carbon content of the constituent (i), expressed as a percentage of the mass of the

constituent (i);
m is the mass of the constituent (i), expressed in grams;
n is the number of constituents of the sample.
3.6.3.2 Calculation as a fraction of total organic carbon (TOC)
The bio-based carbon content of the sample is calculated using Formula (3):
TOC TOC
B ⋅C ⋅m
∑ c,i i i
TOC
i=1
(3)
B = 100
c,s
TOC
C ⋅m
∑ i i
i=1
Where

TOC is the bio-based carbon content, expressed as a percentage of the total organic carbon

c,s
content of the sample;

TOC is the bio-based carbon content of the constituent (i), expressed as a percentage of the total

c,i
organic carbon content of the constituent (i);
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TOC

is the total organic carbon content of the constituent (i), expressed as a percentage of the

mass of the constituent (i);
m is the mass of the constituent (i), expressed in grams;
n is the number of constituents of the sample.
3.6.4 Assessment of deviations of measured 14C values from theoretical values

The stated bio-based content of a sample is validated by comparing the bio-based carbon content determined

by the analysis and the bio-based carbon content obtained by calculation.

Three confidence levels are defined depending on the closeness between the stated value obtained by

calculation and the value obtained by analysis. The stated bio-based content of a sample is validated if the

difference between these values complies with Table 2.
Table 2 — Decision process
Confidence level Deviation between calculation and results of
analysis for the bio-based carbon content
1 (High) ± 3,0
2 (Medium) ± 4,5
3 (Low) ± 6,0

If the difference between the stated value and the value obtained by analysis for bio-based carbon content is

comprised within the uncertainty given in Table 2, then:

a) for confidence level 1, the stated value for the bio-based content is validated;

b) for confidence level 2, the stated value for the bio-based content is rounded down to the nearest "multiple

of five" percentage (e.g. 52 % is rounded down to 50 %, 57 % is rounded down to 55 %);

c) for confidence level 3, the stated value for the bio-based content is rounded down to the second nearest

"multiple of five" percentage in such a way that the difference between the stated value and the rounded

value is > 5 % (e.g. 48 % is rounded down to 40 %, 45,2 % is rounded down to 40 %).

If none of the above conditions are fulfilled, the stated value for the bio-based content is not validated.

EXAMPLE Stated value for the bio-based content: 51 %
Stated value for the bio-based carbon content: 48 %
Measured value for the bio-based carbon content: 44 %
Validated value for the bio-based content:
...

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