EN 902:2016

Chemicals used for treatment of water intended for human consumption - Hydrogen peroxide

This European Standard is applicable only to hydrogen peroxide and not to mixtures with other chemicals used for treatment of water intended for human consumption. It describes the characteristics of hydrogen peroxide and specifies the requirements and the corresponding test methods for hydrogen peroxide. It gives information on its use in water treatment. It also determines the rules relating to safe handling and use (see Annex B).

Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Wasserstoffperoxid

Diese Europäische Norm gilt ausschließlich für Wasserstoffperoxid, nicht jedoch für Mischungen mit anderen Chemikalien, zur Aufbereitung von Wasser für den menschlichen Gebrauch. Es beschreibt die Eigenschaften von Wasserstoffperoxid und legt die Anforderungen sowie die entsprechenden Prüfverfahren für Wasserstoffperoxid fest. Es enthält Angaben für dessen Anwendung in der Wasseraufbereitung. Es legt darüber hinaus Regeln für die sichere Handhabung und Verwendung fest (siehe Anhang B).

Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation humaine - Peroxyde d'hydrogène

Le présent document s’applique uniquement au peroxyde d’hydrogène et ne s’applique pas aux mélanges avec d’autres substances chimiques utilisées pour le traitement de l’eau destinée à la consommation humaine. Il décrit les caractéristiques du peroxyde d’hydrogène et spécifie les exigences et les méthodes d’essai correspondantes. Il donne des informations sur son emploi pour le traitement de l’eau. Il définit également les règles relatives aux précautions d’emploi et de manipulation (voir l’Annexe B).

Kemikalije, ki se uporabljajo za pripravo pitne vode - Vodikov peroksid

Ta dokument se uporablja le za vodikov peroksid, in ne za mešanice z drugimi kemikalijami, ki se uporabljajo za pripravo pitne vode. Opisuje lastnosti vodikovega peroksida ter določa zahteve in ustrezne preskusne metode zanj. Podaja informacije za njegovo uporabo pri pripravi vode. Določa tudi pravila za varno ravnanje in uporabo.

General Information

• Status: Published
• Publication Date: 24-May-2016
• Withdrawal Date: 29-Nov-2016
• ICS: 71.100.80 - Chemicals for purification of water
• Technical Committee: CEN/TC 164 - Water supply
• Drafting Committee: CEN/TC 164/WG 9 - Drinking water treatment
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 21-Mar-2022
• Completion Date: 14-Apr-2025
• Ref Project: SIST EN 902:2016 - Chemicals used for treatment of water intended for human consumption - Hydrogen peroxide

Relations

• Replaces: EN 902:2009 - Chemicals used for treatment of water intended for human consumption - Hydrogen peroxide
• Effective Date: 01-Jun-2016

Overview

EN 902:2016 - published by CEN and approved May 2016 - is the European standard that defines the characteristics, quality requirements and test methods for hydrogen peroxide when used for the treatment of water intended for human consumption. The standard applies specifically to hydrogen peroxide as a single chemical (not to mixtures) and includes guidance on use in water treatment as well as rules for safe handling and storage (see Annex B). EN 902:2016 supersedes EN 902:2009 and is produced by CEN/TC 164 “Water supply”.

Key Topics and Requirements

The standard covers the full technical lifecycle for hydrogen peroxide used in drinking-water applications, including:

• Scope and identification: chemical name, formulas, CAS and EINECS references.
• Physical and chemical properties: appearance, density, solubility, boiling/crystallization points and related parameters.
• Purity criteria: composition of commercial products, impurities and main by‑products, and required chemical parameters.
• Test methods and sampling: sampling rules and analytical methods for determination of hydrogen peroxide content and associated chemical parameters (including methods for trace elements - Annex C covers arsenic, antimony and selenium by hydride AAS).
• Labelling, transportation and storage: delivery forms, EU labelling requirements, transport regulations, container marking and long‑term stability considerations.
• Safety and emergency procedures: normative Annex B provides rules for safe handling, first aid, spillage response and fire procedures.
• Informative guidance: Annex A supplies background on origin, manufacturing, practical use in water treatment (function, dosing, application methods, secondary effects and removal of excess product).

Practical Applications and Users

EN 902:2016 is intended for stakeholders involved in the production, supply, testing and regulatory oversight of chemicals for drinking-water treatment:

• Water utilities and treatment plant operators specifying and using hydrogen peroxide in potable water systems.
• Chemical manufacturers and suppliers ensuring product compliance with European purity, labelling and transport rules.
• Analytical laboratories performing required sampling and test methods to verify product composition and impurities.
• Health, safety and environmental officers managing storage, handling and emergency response for hydrogen peroxide.
• Regulators and standards bodies assessing conformity and alignment with EU biocide legislation (e.g., REGULATION (EU) No 528/2012).

Related Standards

EN 902:2016 references and aligns with other normative documents used in testing and sampling, for example:

• EN ISO 3696 - Water for analytical laboratory use
• EN ISO 12846 - Determination of mercury by AAS
• ISO 3165 / ISO 6206 - Sampling of chemical products for industrial use

EN 902:2016 is an essential reference for safe, compliant use and quality control of hydrogen peroxide in drinking-water applications.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2016
1DGRPHãþD
SIST EN 902:2009
Kemikalije, ki se uporabljajo za pripravo pitne vode - Vodikov peroksid
Chemicals used for treatment of water intended for human consumption - Hydrogen
peroxide
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch -
Wasserstoffperoxid
Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation
humaine - Peroxyde d'hydrogène
Ta slovenski standard je istoveten z: EN 902:2016
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 .HPLNDOLMH]DþLãþHQMHYRGH Chemicals for purification of
water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 902
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2016
EUROPÄISCHE NORM
ICS 71.100.80 Supersedes EN 902:2009
English Version
Chemicals used for treatment of water intended for human
consumption - Hydrogen peroxide
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Peroxyde menschlichen Gebrauch - Wasserstoffperoxid
d'hydrogène
This European Standard was approved by CEN on 18 March 2016.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

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
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 902:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Description . 6
3.1 Identification . 6
3.1.1 Chemical name . 6
3.1.2 Synonym or common name . 6
3.1.3 Relative molecular mass . 6
3.1.4 Empirical formula . 6
3.1.5 Chemical formula . 6
3.1.6 CAS Registry Number . 6
3.1.7 EINECS reference . 7
3.2 Commercial form . 7
3.3 Physical properties . 7
3.3.1 Appearance and odour . 7
3.3.2 Density . 7
3.3.3 Solubility in water . 7
3.3.4 Vapour pressure . 7
3.3.5 Boiling point at 100 kPa . 7
3.3.6 Crystallization point . 8
3.3.7 Specific heat . 8
3.3.8 Viscosity, dynamic . 8
3.3.9 Critical temperature . 9
3.3.10 Critical pressure . 9
3.3.11 Physical hardness . 9
3.4 Chemical properties . 9
4 Purity criteria . 9
4.1 General . 9
4.2 Composition of commercial product . 10
4.3 Impurities and main by-products . 10
4.4 Chemical parameters . 10
5 Test methods . 10
5.1 Sampling . 10
5.2 Analysis . 10
5.2.1 Determination of hydrogen peroxide content (main product) . 10
5.2.2 Chemical parameters . 13
6 Labelling - Transportation - Storage . 15
6.1 Means of delivery . 15
6.2 Labelling according to the EU Legislation . 15
6.3 Transportation regulations and labelling . 19
6.4 Marking . 19
6.5 Storage . 19
6.5.1 Containers . 19
6.5.2 Long term stability . 19
6.5.3 Storage incompatibilities . 20
Annex A (informative) General information on hydrogen peroxide . 21
A.1 Origin . 21
A.1.1 Raw materials . 21
A.1.2 Manufacturing process . 21
A.2 Use . 21
A.2.1 Function . 21
A.2.2 Form in which it is used. 21
A.2.3 Treatment dose . 21
A.2.4 Means of application . 21
A.2.5 Secondary effects . 21
A.2.6 Removal of excess product . 21
A.3 Routine analyses . 22
A.3.1 Determination of chemical parameters . 22
Annex B (normative) General rules relating to safety . 23
B.1 Rules for safe handling and use . 23
B.2 Emergency procedures . 23
B.2.1 First aid . 23
B.2.2 Spillage . 23
B.2.3 Fire . 23
Annex C (normative) Determination of arsenic, antimony and selenium (atomic absorption
spectrometry hydride technique) . 24
C.1 Safety precautions . 24
C.2 General principle . 24
C.3 Interferences . 24
C.4 Reagents . 24
C.5 Apparatus . 26
C.6 Procedure . 28
C.6.1 Preparation of the apparatus . 28
C.6.2 Preparation of calibration solutions . 29
C.6.3 Preparation of test solutions and standard solutions . 29
C.6.4 Determination of arsenic with sodium borohydride . 29
C.6.5 Determination of selenium with sodium borohydride . 29
C.6.6 Determination of antimony with sodium borohydride . 30
C.7 Calculation. 30
Bibliography . 31

European foreword
This document (EN 902:2016) has been prepared by Technical Committee CEN/TC 164 “Water supply”,
the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2016, and conflicting national standards
shall be withdrawn at the latest by November 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN 902:2009.
Significant technical differences between this edition and EN 902:2009 are as follows:
a) deletion of the reference to EU Directive 67/548/EEC of June 27,1967 in order to take into account
the latest Directive in force (see [1]);
b) use of the changed classification and labelling (see [3]).
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: 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 the United Kingdom.
Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused
by the product covered by this European Standard:
1) this European Standard provides no information as to whether the product may be used without
restriction in any of the Member States of the EU or EFTA;
2) it should be noted that, while awaiting the adoption of verifiable European criteria, existing
national regulations concerning the use and/or the characteristics of this product remain in force.
NOTE 1 Conformity with this standard does not confer or imply acceptance or approval of the product in any of
the Member States of the EU or EFTA. The use of the product covered by this European Standard is subject to
regulation or control by National Authorities.
NOTE 2 This product is a biocide and needs to comply with the relevant legislation in force. In the European
Union, at the time of publication, this legislation is REGULATION (EU) No 528/2012 [1].
1 Scope
This European Standard is applicable only to hydrogen peroxide and not to mixtures with other
chemicals used for treatment of water intended for human consumption. It describes the characteristics
of hydrogen peroxide and specifies the requirements and the corresponding test methods for hydrogen
peroxide. It gives information on its use in water treatment. It also determines the rules relating to safe
handling and use (see Annex B).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696)
EN ISO 12846, Water quality — Determination of mercury — Method using atomic absorption
spectrometry (AAS) with and without enrichment (ISO 12846)
ISO 3165, Sampling of chemical products for industrial use — Safety in sampling
ISO 6206, Chemical products for industrial use — Sampling — Vocabulary
ISO 8288, Water quality — Determination of cobalt, nickel, copper, zinc, cadmium and lead — Flame
atomic absorption spectrometric methods
ISO 9174, Water quality — Determination of chromium — Atomic absorption spectrometric methods
3 Description
3.1 Identification
3.1.1 Chemical name
Hydrogen peroxide.
3.1.2 Synonym or common name
None.
3.1.3 Relative molecular mass
34,02.
3.1.4 Empirical formula
H O .
2 2
3.1.5 Chemical formula
H-O-O-H.
1)
3.1.6 CAS Registry Number
7722-84-1.
1) Chemical Abstracts Service Registry Number.
2)
3.1.7 EINECS reference
231-765-0.
3.2 Commercial form
The product is supplied as an aqueous solution.
3.3 Physical properties
3.3.1 Appearance and odour
The product is colourless liquid, slightly pungent odour.
3.3.2 Density
The density of hydrogen peroxide is given in Table 1.
Table 1 — Density
Solution concentration Density
Mass fraction in% g/ml at 20 °C
20 1,075
30 1,114
35 1,132
50 1,195
60 1,241
70 1,289
3.3.3 Solubility in water
The product is miscible with water in all proportions.
3.3.4 Vapour pressure
The vapour pressure of hydrogen peroxide depending on concentration is given in Table 2.
Table 2 — Vapour pressure
Solution concentration Vapour pressure
Mass fraction in % kPa at 20 °C
20 2,0
30 1,8
35 1,7
50 1,3
60 1,1
70 0,8
3)
3.3.5 Boiling point at 100 kPa
The boiling point of hydrogen peroxide depending on concentration is given in Table 3.

2) European Inventory of Existing Commercial Chemical Substances.
3) 100 kPa = 1 bar.
Table 3 — Boiling point
Solution concentration Boiling point
Mass fraction in % °C at 100 kPa
20 103
30 106
35 108
50 114
60 119
70 125
3.3.6 Crystallization point
The crystallization point of hydrogen peroxide depending on concentration is given in Table 4.
Table 4 — Crystallization point
Solution concentration Crystallization point
Mass fraction in % °C
20 – 14,6
30 – 25,7
35 – 32,5
50 – 51
60 – 55
70 – 37
3.3.7 Specific heat
The specific heat of hydrogen peroxide depending on concentration is given in Table 5.
Table 5 — Specific heat
Solution concentration Specific heat
Mass fraction in % kJ/(kg.K)
20 3,82 at 20 °C
50 3,32 at 20 °C
100 2,63 at 25 °C
3.3.8 Viscosity, dynamic
The viscosity of hydrogen peroxide depending on concentration is given in Table 6.
Table 6 — Viscosity
Solution concentration Viscosity
Mass fraction in % MPa.s at 20 °C
20 1,04
30 1,07
35 1,10
50 1,17
60 1,20
70 1,24
100 1,25
3.3.9 Critical temperature
The critical temperature of pure hydrogen peroxide is 457 °C.
3.3.10 Critical pressure
The critical pressure of pure hydrogen peroxide is 21,7 mPa.
3.3.11 Physical hardness
Not applicable.
3.4 Chemical properties
Hydrogen peroxide is a weak acid.
According to species in solution, it is an oxidizing agent (E° = 1,776 V) or a reducing agent
(E ° = 0,682 V).
Oxidizing agent:
+ -
H O + 2H + 2e ––- > 2H O
2 2 2
Reducing agent:
+ -
H O ––- > O + 2H + 2e
2 2 2
NOTE 1 It can be activated by ultraviolet light, ozone or metals to generate free radicals.
NOTE 2 Singlet oxygen can be obtained by reaction of hydrogen peroxide with hypochlorite ion.
4 Purity criteria
4.1 General
This European Standard specifies the minimum purity requirements for hydrogen peroxide used for the
treatment of water intended for human consumption. Limits are given for impurities commonly present
in the product. Depending on the raw material and the manufacturing process other impurities may be
present and, if so, this shall be notified to the user and when necessary to relevant authorities.
Users of this product should check the national regulations in order to clarify whether it is of
appropriate purity for treatment of water intended for human consumption, taking into account raw
water quality, required dosage, contents of other impurities and additives used in the product not
stated in this product standard.
Limits have been given for impurities and chemicals parameters where these are likely to be present in
significant quantities from the current production process and raw materials. If the production process
or raw materials lead to significant quantities of impurities, by-products or additives being present, this
shall be notified to the user.
4.2 Composition of commercial product
The hydrogen peroxide is usually available in concentrated solution with concentration within the
range of mass fraction of 20 % to 70 %. Diluted products are also available.
The concentration of hydrogen peroxide shall be equal to or greater than the manufacturer specified
value.
4.3 Impurities and main by-products
Not applicable.
4.4 Chemical parameters
The product shall conform to the requirements specified in Table 7.
Table 7 — Chemical parameters
Parameter  Limit in mg/kg of product
(mass fraction 100 %)
Type 1 Type 2
Arsenic (As) max. 0,5 1
Cadmium (Cd) max. 0,5 1
Chromium (Cr) max. 0,5 1
Mercury (Hg) max. 0,5 1
Nickel (Ni) max. 1 5
Lead (Pb) max. 0,5 1
Antimony (Sb) max. 0,5 1
Selenium (Se) max. 0,5 1
NOTE Cyanide which does not exist in a strong oxidizing medium such
as hydrogen peroxide is not a relevant chemical parameter. Pesticides and
polycyclic aromatic hydrocarbons are not by-products of the manufacturing
process. For parametric values of chemical parameters in drinking water,
see [2].
5 Test methods
5.1 Sampling
Observe the general recommendations of ISO 3165 and take ISO 6206 into account.
5.2 Analysis
5.2.1 Determination of hydrogen peroxide content (main product)
5.2.1.1 Principle
Titration of a test portion of hydrogen peroxide in acidic medium with a potassium permanganate
standard volumetric solution.
5.2.1.2 Reagents
All reagents shall be of a recognized analytical grade and the water used shall conform to grade 3 in
accordance with EN ISO 3696.
5.2.1.2.1 Sulfuric acid, solution, free from reducing substance, 440 g/l:
Check for the absence of reducing substances by adding two drops of the potassium permanganate
solution (5.2.1.2.2) to 1 l of the sulfuric acid solution. The pink coloration shall persist for at least
30 min.
5.2.1.2.2 Potassium permanganate, standard volumetric solution, c(KMnO ) = 0,1 mol/l.
Weigh about 16 g of potassium permanganate (KMnO ) and dissolve in 1 l of water.
Mix the solution and store it in a coloured, ground glass stoppered bottle for at least 10 days before
standardizing.
The standardization shall be carried out in accordance with the following procedure:
a) Preparation of the sodium oxalate, standard volumetric solution, c(Na C O ) = 0,25 mol/l:
2 2 4
Dry the sodium oxalate (Na C O ) at 200 °C for 24 h and allow to cool in a desiccator. Weigh to the
2 2 4
nearest 0,000 1 g, 16,75 g of this product and dissolve it in 200 ml of the sulfuric acid
solution (5.2.1.2.1). Transfer the solution quantitatively to a 500 ml one-mark volumetric flask, dilute to
the mark with water and mix.
Store the solution in a coloured, ground glass stoppered bottle. Store for at least 3 days before using and
discard after 30 d.
b) Determination of the concentration:
Introduce 50 ml (V ) of the sodium oxalate solution (a) into a 500 ml conical flask and add 45 ml of
water and 15 ml of the sulfuric acid solution (5.2.1.2.1).
Heat the mixture to 40 °C by means of a hot water bath. Using a burette, quickly add 38 ml of the
potassium permanganate solution (5.2.1.2.2.). Discoloration shall occur after shaking for several
seconds; if necessary raise the temperature of the test solution slightly. Continue adding the potassium
permanganate solution, drop by drop, until a pink coloration is obtained which persists for 30 s. Note
the volume V
.
c) Calculation:
The concentration (c ) of the potassium permanganate solution (5.2.1.2.2) expressed in moles per litre
is given by the following formula:
c = 2/5 × (c × V )/V (1)
2 1 1 2
where
c1 is the concentration, in moles per litre, of the sodium oxalate solution used for the titration
in c) (c = 0,25 mol/l);
V is the volume, in millilitres, of the sodium oxalate solution used for the titration in b)
(V = 50,00 ml);
V is the volume, in millilitres, of the potassium permanganate solution used for the titration in
b).
5.2.1.3 Apparatus
Ordinary laboratory apparatus and glassware together with glass containers, about 10 mm in diameter
and 20 mm long.
5.2.1.4 Procedure
5.2.1.4.1 Test portion
Depending on the concentration of the test sample, weigh, to the nearest 0,000 1 g, into one of the clean
glass containers (5.2.1.3) the mass of the test sample (m ) indicated below:
— about 1,1 g for H O solutions with concentration of mass fraction 35 %;
2 2
— about 0,75 g for H O solutions with a concentration of mass fraction 50 %;
2 2
— about 0,55 g for H O solutions with a concentration of mass fraction 70 %.
2 2
5.2.1.4.2 Determination
Introduce 60 ml of water and 15 ml of the sulfuric acid solution (5.2.1.2.1) into a 500 ml conical flask.
Add the potassium permanganate solution (5.2.1.2.2), drop by drop, shaking continuously, until a slight
pink coloration is obtained which persists for 30 s (one drop is usually sufficient).
Add the test portion in the glass container and titrate with the potassium permanganate standard
volumetric solution (5.2.1.2.2) until a pink coloration is obtained which persists for 30 s. Record the
volume (V ).
NOTE The determination can be easily automated using automatic titration apparatus which gives an end
point in 15 s to 20 s.
5.2.1.5 Expression of results
The concentration of hydrogen peroxide (c ), expressed in mass fraction in % is given by the following
formula:
c = 5/2 × (c × V × M)/(m × 10) (2)
3 2 3 0
where
V is the volume, in millilitres, of the potassium permanganate standard volumetric standard
volumetric solution (5.2.1.2.2) used for the determination;
c is the concentration, in moles per litre, of the potassium permanganate standard volumetric
solution (5.2.1.2.2);
m is the mass, in grams, of the test portion (5.2.1.4.1);
M is the molecular mass of hydrogen peroxide (M = 34,01 g/mol).
Express the result to the second significant figure.
5.2.2 Chemical parameters
5.2.2.1 Determination of antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb),
nickel (Ni) and selenium (Se)
5.2.2.1.1 Principle
The elements arsenic, antimony, cadmium, chromium, lead, nickel and selenium are determined by
atomic absorption spectrometry.
5.2.2.1.2 Reagents
All reagents shall be of a recognized analytical grade and the water used shall conform to the
appropriate grade specified in EN ISO 3696.
5.2.2.1.2.1 Nitric acid, concentrated, density ρ = 1,42 g/ml.
5.2.2.1.3 Procedure
5.2.2.1.3.1 Test portion
Weigh, to the nearest 0,001 g,
...