SIST EN ISO 23977-2:2022
(Main)Plastics - Determination of the aerobic biodegradation of plastic materials exposed to seawater - Part 2: Method by measuring the oxygen demand in closed respirometer (ISO 23977-2:2020)
Plastics - Determination of the aerobic biodegradation of plastic materials exposed to seawater - Part 2: Method by measuring the oxygen demand in closed respirometer (ISO 23977-2:2020)
This document specifies a laboratory test method for determining the degree and rate of the aerobic biodegradation level of plastic materials. Biodegradation of plastic materials is determined by measuring the oxygen demand in a closed respirometer when exposed to seawater sampled from coastal areas under laboratory conditions.
The conditions described in this document might not always correspond to the optimum conditions for the maximum degree of biodegradation, however this test method is designed to give an indication of the potential biodegradability of plastic materials.
NOTE This document addresses plastic materials but can also be used for other materials.
Kunststoffe - Bestimmung des aeroben Bioabbaus von Meerwasser ausgesetzten Kunststoff-Materialien - Teil 2: Verfahren mittels Messung des Sauerstoffbedarfs in einem geschlossenen Respirometer (ISO 23977-2:2020)
Dieses Dokument legt ein Laborprüfverfahren für die Bestimmung des Grads und der Geschwindigkeit des aeroben Bioabbaus von Kunststoffmaterialien fest. Der Bioabbau von Kunststoffmaterialien wird durch die Messung des Sauerstoffbedarfs in einem geschlossenen Respirometer bei Kontakt mit Meerwasser aus Küstenbereichen unter Laborbedingungen bestimmt.
Die in diesem Dokument beschriebenen Bedingungen entsprechen möglicherweise nicht immer den optima¬len Bedingungen für den maximalen Grad des Bioabbaus, jedoch ist dieses Prüfverfahren dafür ausgelegt, einen Hinweis auf die potentielle Bioabbaubarkeit von Kunststoffmaterialien zu liefern.
ANMERKUNG Dieses Dokument behandelt Kunststoffmaterialien, kann aber auch für andere Materialien verwendet werden.
Plastiques - Détermination de la biodégradation aérobie des matières plastiques exposées à l'eau de mer - Partie 2: Méthode par mesure de la demande en oxygène dans un respiromètre fermé (ISO 23977-2:2020)
Le présent document spécifie une méthode d’essai en laboratoire permettant de déterminer le taux et le niveau de biodégradation aérobie des matériaux plastiques. La biodégradation des matériaux plastiques est déterminée en mesurant la demande en oxygène dans un respiromètre fermé lorsqu’ils sont exposés à de l’eau de mer prélevée dans des zones côtières, dans des conditions de laboratoire.
Les conditions décrites dans le présent document ne correspondent pas nécessairement aux conditions optimales permettant d’obtenir le taux maximal de biodégradation; cependant, cette méthode d’essai est conçue pour donner une indication de la biodégradabilité potentielle des matériaux plastiques.
NOTE Le présent document concerne les matériaux plastiques, mais il peut aussi être utilisé pour d’autres matériaux.
Polimerni materiali - Določanje aerobne biorazgradljivosti polimernih materialov, izpostavljenih morski vodi - 2. del: Metoda z merjenjem porabe kisika v zaprtem respirometru (ISO 23977-2:2020)
Ta dokument določa laboratorijsko preskusno metodo za določevanje stopnje in hitrosti aerobne biorazgradljivosti polimernih materialov. Biorazgradljivost polimernih materialov se določi z merjenjem porabe kisika v zaprtem respirometru ob izpostavljenosti morski vodi, vzorčeni iz obalnih območij pod laboratorijskimi pogoji.
Pogoji, ki so opisani v tem dokumentu, morda niso vedno enaki idealnim pogojem, pri katerih pride do največje stopnje biorazgradljivosti, vendar je ta preskusna metoda zasnovana tako, da podaja oceno potencialne biorazgradljivosti polimernih materialov.
OPOMBA: Ta dokument obravnava polimerne materiale, vendar ga je mogoče uporabiti tudi za druge materiale.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2022
Polimerni materiali - Določanje aerobne biorazgradljivosti polimernih materialov,
izpostavljenih morski vodi - 2. del: Metoda z merjenjem porabe kisika v zaprtem
respirometru (ISO 23977-2:2020)
Plastics - Determination of the aerobic biodegradation of plastic materials exposed to
seawater - Part 2: Method by measuring the oxygen demand in closed respirometer (ISO
23977-2:2020)
Kunststoffe - Bestimmung des aeroben Bioabbaus von Meerwasser ausgesetzten
Kunststoff-Materialien - Teil 2: Verfahren mittels Messung des Sauerstoffbedarfs in
einem geschlossenen Respirometer (ISO 23977-2:2020)
Plastiques - Détermination de la biodégradation aérobie des matières plastiques
exposées à l'eau de mer - Partie 2: Méthode par mesure de la demande en oxygène
dans un respiromètre fermé (ISO 23977-2:2020)
Ta slovenski standard je istoveten z: EN ISO 23977-2:2021
ICS:
13.020.40 Onesnaževanje, nadzor nad Pollution, pollution control
onesnaževanjem in and conservation
ohranjanje
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 23977-2
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2021
EUROPÄISCHE NORM
ICS 83.080.01
English Version
Plastics - Determination of the aerobic biodegradation of
plastic materials exposed to seawater - Part 2: Method by
measuring the oxygen demand in closed respirometer (ISO
23977-2:2020)
Plastiques - Détermination de la biodégradation Kunststoffe - Bestimmung des aeroben Bioabbaus von
aérobie des matières plastiques exposées à l'eau de Meerwasser ausgesetzten Kunststoff-Materialien - Teil
mer - Partie 2: Méthode par mesure de la demande en 2: Verfahren mittels Messung des Sauerstoffbedarfs in
oxygène dans un respiromètre fermé (ISO 23977- einem geschlossenen Respirometer (ISO 23977-
2:2020) 2:2020)
This European Standard was approved by CEN on 8 November 2021.
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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23977-2:2021 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
The text of ISO 23977-2:2020 has been prepared by Technical Committee ISO/TC 61 "Plastics” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 23977-2:2021
by Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN.
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 May 2022, and conflicting national standards shall be
withdrawn at the latest by May 2022.
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.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 23977-2:2020 has been approved by CEN as EN ISO 23977-2:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 23977-2
First edition
2020-11
Plastics — Determination of the
aerobic biodegradation of plastic
materials exposed to seawater —
Part 2:
Method by measuring the oxygen
demand in closed respirometer
Plastiques — Détermination de la biodégradation aérobie des
matières plastiques exposées à l'eau de mer —
Partie 2: Méthode par mesure de la demande en oxygène dans un
respiromètre fermé
Reference number
ISO 23977-2:2020(E)
©
ISO 2020
ISO 23977-2:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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.
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
ISO 23977-2:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Test environment . 3
6 Reagents . 3
7 Apparatus . 4
8 Procedure. 5
8.1 Test material . 5
8.2 Reference materials . 6
8.3 Test set up . 6
8.4 Pre-conditioning phase . 6
8.5 Start of the test . 7
8.6 End of the test . 7
9 Calculation and expression of results . 7
9.1 Calculation . 7
9.2 Visual inspection . 8
9.3 Expression and interpretation of results . 8
10 Validity of results . 9
11 Test report . 9
Annex A (informative) Example of a respirometric system .10
Bibliography .12
ISO 23977-2:2020(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 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 61, Plastics, Subcommittee SC 14,
Environmental aspects.
A list of all parts in the ISO 23997 series can be found on the ISO website.
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 © ISO 2020 – All rights reserved
ISO 23977-2:2020(E)
Introduction
According to the United Nations Environment Program (UNEP), one of the most notable properties of
synthetic polymers and plastics is their durability which, combined with their accidental loss, deliberate
release and poor waste management has resulted in the ubiquitous presence of plastic in oceans (UNEP,
[15]
2015 ).
It is well known and documented that marine litter can pose risks and a negative impact on living
marine organisms and on human beings. Degradability of plastic materials exposed to the marine
environment is one of the factors affecting impact and strength of effects. The uncontrolled dispersion
of biodegradables plastics in natural environments is not desirable. The biodegradability of products
cannot be considered as an excuse to spread wastes that should be recovered and recycled. However,
test methods to measure rate and level of biodegradation in natural environments are of interest in
order to better characterize the behaviour of plastics in these very particular environments. Thus, the
degree and rate of biodegradation is of major interest in order to obtain an indication of the potential
biodegradability of plastic materials when exposed to different marine habitats.
ISO/TC 61/SC 14 has established several test methods for biodegradation testing of plastic materials
under laboratory conditions covering different environmental compartments and test conditions, as
shown in Table 1.
Table 1 — Test methods for biodegradation testing of plastics
Conditions
Test methods
Environmental compartment Presence/absence of oxygen
ISO 14855-1
Controlled composting conditions Aerobic conditions
ISO 14855-2
High-solids anaerobic-digestion
Anaerobic conditions ISO 15985
conditions
Controlled anaerobic slurry system Anaerobic conditions ISO 13975
Soil Aerobic conditions ISO 17556
ISO 14851
Aerobic conditions
Aqueous medium ISO 14852
Anaerobic conditions ISO 14853
a
ISO 18830
Seawater/sandy sediment interface Aerobic conditions
a
ISO 19679
a
Marine sediment Aerobic conditions ISO 22404
a
ISO 23977-1
Seawater Aerobic conditions
a
ISO 23977-2
a
Test method for measuring biodegradation of plastic materials when exposed to marine microbes.
All marine biodegradation test methods are based on exposure of plastic materials to marine samples
(seawater and/or sediment) taken from shoreline areas. By a quantitative viewpoint, these methods
are not equivalent, because, for example, the microbial density in seawater is generally lower compared
to the density determined in sediment. In addition, the microbial composition and diversity can be
different. Moreover, as a rule, the nutrient concentration found in sediment is normally higher compared
to the concentration in seawater.
This document provides a test method for determining the biodegradation level of plastic materials
exposed to the microbial population present in seawater from a pelagic zone under laboratory
conditions. The biodegradation is followed by measuring the oxygen demand in a closed respirometer.
The test is performed with either seawater only (“pelagic seawater test”) or with seawater to which
little sediment was added (“suspended sediment seawater test”).
ISO 23977-2:2020(E)
The pelagic seawater test simulates the conditions found in offshore areas with low water currents and
low tidal movements, whereas the suspended sediment seawater test simulates conditions which might
be found in coastal areas with stronger water currents and tidal movements.
vi © ISO 2020 – All rights reserved
INTERNATIONAL STANDARD ISO 23977-2:2020(E)
Plastics — Determination of the aerobic biodegradation of
plastic materials exposed to seawater —
Part 2:
Method by measuring the oxygen demand in closed
respirometer
1 Scope
This document specifies a laboratory test method for determining the degree and rate of the aerobic
biodegradation level of plastic materials. Biodegradation of plastic materials is determined by
measuring the oxygen demand in a closed respirometer when exposed to seawater sampled from
coastal areas under laboratory conditions.
The conditions described in this document might not always correspond to the optimum conditions for
the maximum degree of biodegradation, however this test method is designed to give an indication of
the potential biodegradability of plastic materials.
NOTE This document addresses plastic materials but can also be used for other materials.
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 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 8245, Water quality — Guidelines for the determination of total organic carbon (TOC) and dissolved
organic carbon (DOC)
ISO 10210, Plastics — Methods for the preparation of samples for biodegradation testing of plastic
materials
ISO 10523, Water quality — Determination of pH
ISO 11261, Soil quality — Determination of total nitrogen — Modified Kjeldahl method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
pelagic zone
water body above the seafloor
Note 1 to entry: It is also referred to as the open water or the water column.
ISO 23977-2:2020(E)
Note 2 to entry: The surface of the pelagic zone is moved by wind-driven waves, is in contact with the atmosphere
and exposed to sunlight. With increasing depth pressure increases, temperature decreases, and light and surface
wave energy are attenuated.
[SOURCE: ISO 22766:2020, 3.4]
3.2
biochemical oxygen demand
BOD
mass concentration of the dissolved oxygen consumed under specified conditions by the aerobic
biological oxidation of a chemical compound or organic matter in water
Note 1 to entry: It is expressed as milligrams of oxygen uptake per milligram or gram of test compound.
[SOURCE: ISO 18830:2016, 3.1]
3.3
theoretical oxygen demand
ThOD
theoretical maximum amount of oxygen required to oxidize a chemical compound completely, calculated
from the molecular formula
Note 1 to entry: It is expressed as milligrams of oxygen uptake per milligram or gram of test compound.
[SOURCE: ISO 18830:2016, 3.2]
3.4
total organic carbon
TOC
amount of carbon bound in an organic compound
Note 1 to entry: It is expressed as milligrams of carbon per 100 mg of the compound.
[SOURCE: ISO 17556:2019, 3.14]
3.5
dissolved organic carbon
DOC
part of the organic carbon in water which cannot be removed by specified phase separation
−2
Note 1 to entry: Phase separation can be achieved for example by centrifugation at 40 000 m⋅s for 15 min or by
membrane filtration using membranes with pores of 0,2 μm to 0,45 μm diameter.
[SOURCE: ISO 14852:—, 3.7]
3.6
lag phase
time from the start of a test until adaptation and/or selection of the degrading microorganisms is
achieved and the degree of biodegradation of a chemical compound or organic matter has increased to
about 10 % of the maximum level of biodegradation (3.8)
Note 1 to entry: It is measured in days.
[SOURCE: ISO 14852:—, 3.8]
3.7
biodegradation phase
time from the end of the lag phase (3.6) of a test until the plateau phase has been reached
Note 1 to entry: It is measured in days.
[SOURCE: ISO 14852:—, 3.10]
2 © ISO 2020 – All rights reserved
ISO 23977-2:2020(E)
3.8
maximum level of biodegradation
degree of biodegradation of a chemical compound or organic matter in a test, above which no further
biodegradation takes place during the test
Note 1 to entry: It is measured in per cent.
[SOURCE: ISO 14852:—, 3.9]
3.9
plateau phase
time from the end of the biodegradation phase (3.7) until the end of a test
Note 1 to entry: It is measured in days.
[SOURCE: ISO 14852:—, 3.11]
3.10
pre-conditioning
pre-incubation of an inoculum under the conditions of the subsequent test in the absence of the chemical
compound or organic matter under test, with the aim of improving the test by acclimatization of the
microorganisms to the test conditions
[SOURCE: ISO 14852:—, 3.13]
4 Principle
This document describes two variations of a test method for determining the biodegradability of plastic
materials by the indigenous population of microorganisms in natural seawater using a static aqueous
test system. The test is performed under mesophilic test conditions for up to two years by incubating
plastic materials with either seawater only (“pelagic seawater test”) or with seawater to which low
amount of sediment has been added (“suspended sediment seawater test”), coming from the same site
as that from which the seawater was taken.
The system is contained in a closed flask, in a respirometer. The carbon dioxide evolved is absorbed
in a suitable absorber in the headspace of the flasks. The consumption of oxygen (BOD) is determined,
for example, by measuring the amount of oxygen required to maintain a constant volume of gas in the
respirometer flasks, or by measuring the change in volume or pressure (or a combination of the two)
either automatically or manually.
The level of biode
...
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