SIST EN ISO 22766:2022

SLOVENSKI STANDARD
oSIST prEN ISO 22766:2021
01-september-2021
Polimerni materiali - Ugotavljanje stopnje razpada polimernih materialov v morskih
habitatih v realnih terenskih pogojih (ISO 22766:2020)
Plastics - Determination of the degree of disintegration of plastic materials in marine
habitats under real field conditions (ISO 22766:2020)
Kunststoffe - Bestimmung des Zersetzungsgrades von Kunststoff-Materialien in marinen
Lebensräumen unter realen Feldbedingungen (ISO 22766:2020)
Plastiques - Détermination du degré de désintégration des matériaux plastiques dans les
habitats marins en conditions réelles (ISO 22766:2020)
Ta slovenski standard je istoveten z: prEN ISO 22766
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
oSIST prEN ISO 22766:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 22766:2021

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oSIST prEN ISO 22766:2021
INTERNATIONAL ISO
STANDARD 22766
First edition
2020-03
Plastics — Determination of the
degree of disintegration of plastic
materials in marine habitats under
real field conditions
Plastiques — Détermination du degré de désintégration des
matériaux plastiques dans les habitats marins en conditions réelles
Reference number
ISO 22766:2020(E)
©
ISO 2020

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oSIST prEN ISO 22766:2021
ISO 22766:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© 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.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

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oSIST prEN ISO 22766:2021
ISO 22766:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Test procedure . 3
5.1 Test material . 3
5.2 Reference material . 4
5.3 Preparation of test and reference materials . 4
5.4 Number of replicates . 4
5.5 Exposure to marine habitats . 5
5.6 Termination of the field test . 5
6 Analysis and monitoring of the field test . 6
6.1 Photographic documentation . 6
6.2 Determination of disintegration . 6
6.2.1 General. 6
6.2.2 Sieving procedure . 6
6.2.3 Image analysis (photogrammetry) . 7
6.3 Analysing characteristics of plastic materials (optional) . 8
6.4 Monitoring environmental parameters (optional) . 8
7 Demonstration of a biologically active marine environment (optional) .9
8 Test report . 9
Annex A (normative) Exposure to the sublittoral zone .10
Annex B (normative) Exposure to the eulittoral zone .12
Annex C (informative) Example of image analysis (photogrammetry) .15
Bibliography .17
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oSIST prEN ISO 22766:2021
ISO 22766:2020(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.
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.
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oSIST prEN ISO 22766:2021
ISO 22766:2020(E)

Introduction
Even though plastics that are biodegradable according to established land-based treatment standards
are not and never were intended as a solution to marine littering, the United Nations Environment
Programme (UNEP) recognizes that "biodegradability in seawater" can be part of the solution
(EuBP, 2016; UNEP, 2016). Hence, plastic materials that are biodegradable might be used as a potential
alternative option in order to reduce the residence time of plastic waste in case of dispersion. Thus, the
degree and rate of disintegration is of interest in order to determine the durability of products when
exposed to the marine environment and the physical disappearance of waste in case of dispersal.
This document describes a disintegration test performed in two different marine habitats under
real field conditions. The relative durability of plastic materials of the same size and form may vary
depending on the location of the exposure, seasonal variations, the climatic conditions, water movement,
tides, availability of nutrients, and diversity and density of the competent microbial community. Hence,
it is recommended to perform the disintegration test in regions where the plastic material is likely to
end up in the coastal environment for accidental or deliberate reasons.
This document describes a disintegration test and not a biodegradation test, as the conversion of the
plastic materials is not determined by means of measuring the O -consumption or the CO -evolution.
2 2
The assessment of the intrinsic aerobic biodegradability of plastic materials exposed to marine
environment is covered by ISO 22403.
The determination of the degradation and durability of plastic materials floating on the surface of
seawater or partially or completely immersed in coastal shallow seawater under real field conditions is
covered by ISO 15314.
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oSIST prEN ISO 22766:2021

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oSIST prEN ISO 22766:2021
INTERNATIONAL STANDARD ISO 22766:2020(E)
Plastics — Determination of the degree of disintegration
of plastic materials in marine habitats under real field
conditions
1 Scope
This document specifies test methods for the determination of the degree of disintegration of plastic
materials exposed to marine habitats under real field conditions.
The marine areas under investigation are the sandy sublittoral and the sandy eulittoral zone where
plastic materials can either be placed intentionally (e.g. biodegradable fishing nets) or end up as litter
due to irresponsible human behaviour. This depends on their physical characteristics, form and size of
the materials, and on water currents and tidal movements.
This document specifies the general requirements of the apparatus, and the procedures for using the
test methods described.
The determination of the level of disintegration of plastic materials exposed to pelagic zones such as
the sea surface or the water column above the seafloor are not within the scope of this document.
This document is not suitable for the assessment of disintegration caused by heat or light exposure.
The described field test is a disintegration test and not a biodegradation test. Therefore, it cannot be
used for demonstrating biodegradation or for making unqualified claims such as “biodegradable in
marine environment” and similar.
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 3310-2, Test sieves — Technical requirements and testing — Part 2: Test sieves of perforated metal plate
ISO 4591, Plastics — Film and sheeting — Determination of average thickness of a sample, and average
thickness and yield of a roll, by gravimetric techniques (gravimetric thickness)
ISO 4593, Plastics — Film and sheeting — Determination of thickness by mechanical scanning
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ASTM E11, Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves
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/
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oSIST prEN ISO 22766:2021
ISO 22766:2020(E)

3.1
biodegradation
degradation (3.2) caused by biological activity, especially by enzymatic action, leading to a significant
change in the chemical structure of a material
[SOURCE: ISO 472:2013, 2.1680]
3.2
degradation
irreversible process leading to a significant change in the structure of a material, typically characterized
by a change of properties (e.g. integrity, molecular mass or structure, mechanical strength) and/or by
fragmentation, affected by environmental conditions, proceeding over a period of time and comprising
one or more steps
[SOURCE: ISO 472:2013, 2.262]
3.3
disintegration
physical breakdown of a material into small fragments
[SOURCE: ISO 472:2013, 2.1757]
3.4
pelagic zone
water body above the seafloor
Note 1 to entry: Also referred to as the open water or the water column.
Note 2 to entry: The surface of the pelagic zone is moved by wind-driven waves. It is in contact with the
atmosphere and exposed to sunlight. With increasing depth pressure increase, temperature decreases, and light
and surface wave energy are attenuated.
3.5
sublittoral zone
coastal seafloor that is permanently immersed and extends from the low-water line to the continental
shelf edge at 200 m water depth
Note 1 to entry: The seafloor can consist of solid rock, or fragments that form sediments of different particle size,
from coarse blocks and pebbles, to permeable sands, silt and clay. Sediments can form from fragmented rock or
consist of fragments of biogenic origin (algae, shells, coral, etc.), or be a mixture of these compounds.
3.6
tidal zone
borderline between sea and land that extends from the high tide line, which is rarely inundated with
water, to the low tide line, which is typically always covered with water
Note 1 to entry: The tidal zone is frequently a sandy area that is kept constantly damp by the lapping of the waves.
Note 2 to entry: Stony and rocky shorelines also exist.
Note 3 to entry: Synonyms are: eulittoral zone, midlittoral zone, mediolittoral zone, intertidal zone, foreshore.
[SOURCE: ISO 22404:2019, 3.1]
3.7
total dry solids
amount of solids obtained by taking a known volume of test material or compost and drying at about
105 °C to constant mass
[SOURCE: ISO 472:2013, 2.1872]
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3.8
volatile solids
amount of solids obtained by subtracting the residues of a known volume of test material or compost
after incineration at about 550 °C from the total dry solids (3.7) content of the same sample
Note 1 to entry: The volatile solids content is an indication of the amount of organic matter present.
[SOURCE: ISO 472:2013, 2.1889]
4 Principle
The disintegration test is a real field test performed under natural environmental conditions in two
different coastal regions. Concerned habitats are the eulittoral and the sublittoral zone where plastic
materials can end up once dispersed in the sea.
NOTE Plastic materials predominately floating in pelagic zone are not covered by this document.
The test material, preferably in the form of a film, is fixed in non-degradable plastic frames and both
sides of the material are protected by a plastic mesh with limited defined mesh size (2 mm) in order to
avoid sample loss once the disintegration process has started. Several frames with fixed test specimens
are exposed to the eulittoral zone where the material is subjected to the tides and severely fluctuating
weather conditions, and to the seawater - sediment interface in the sublittoral zone where less rough
environmental conditions are likely to be expected.
The disintegration is determined and reported after an exposure period of three years. However, the
disintegration can be investigated in additional samples with exposure periods below or beyond three
years, provided that the test procedure and the test evaluation are in accordance with this document.
At the end of the exposure period, the disintegration of the test material is measured by means of
removing the protection mesh and sieving the remaining material through 2 mm mesh sieve. The
disintegration of the test material is evaluated by comparing the residual material (total dry solids)
retained by the 2 mm sieve by the amount introduced (total dry solids).
Alternatively, the disintegration of the test material can be determined as area loss (%) by means of
image analysis (photogrammetry). Images of sampled test material specimen are analysed for the ratio
between the disintegrated area versus total area of exposed film.
Even if results from different exposure periods are available indicating a constant increase of the
disintegration of a test material, it is not allowed to extrapolate the degree of disintegration beyond the
maximum exposure period.
5 Test procedure
5.1 Test material
Use the test material preferably in the form of film in an identical form (e.g. shape, thickness) as for the
intended final use. The thickness of a film shall be either determined according ISO 4591 or ISO 4593.
Other forms than films, for instance articles such as foams or plates, can also be tested if test procedure
and test evaluation are in accordance with this document.
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oSIST prEN ISO 22766:2021
ISO 22766:2020(E)

5.2 Reference material
1)
A poly(3-hydroxybutyrate-co-hexanoate) (PHBH) film of 25 μm to 30 µm thickness shall be used
as a positive control. As a negative control a low-density polyethylene (PE-LD) film of 25 μm to30 µm
thickness shall be used.
5.3 Preparation of test and reference materials
Test samples shall not be subjected to conditions or procedures, such as a pretreatment by heat and/
or an exposure to radiation, designed to accelerate disintegration prior to testing according to this
document.
A plastic material preferably in the form of a film is cut into pieces of 260 mm × 200 mm in size. A test
specimen is covered with a non-degradable plastic mesh with a 2 mm × 2 mm mesh size on both sides
to prevent eventual fragments from being lost. Use meshes of suitable shape with a screen of 2 mm as
specified for instance in ASTM E11. The specimen covered by the meshes is then fixed between two
non-degradable plastic frames of 260 mm × 200 mm and 200 mm × 160 mm external and internal
dimension, respectively (see Figure 1). Typical non-biodegradable meshes are made of polyamide,
polyethylene or polypropylene. The surface area of the film specimen which is exposed to the marine
2
habitats is 320 cm .
2
Film specimen that is 200 mm × 160 mm in size (surface area 320 cm ) can be used as an alternative
fitting in the inner part of the plastic frame not fixed between two non-degradable plastic frames.
The film is still covered by non-degradable plastic mesh preventing the loss of material during the
exposure period.
Figure 1 — Film specimen covered with a non-degradable plastic mesh and fixed between two
non-degradable plastic frames
5.4 Number of replicates
Provide a sufficient number of samples prepared according to 5.3, at least:
— five frames for the test material (F 1-5)
T
— five frames for the positive reference material (F 1-5)
pR
1)  Supplier of PHBH-pellets: www .kaneka .be/ documents/ PHBH -brochure -11 -2017 .pdf. Use pellets to blow a
film of 25 μm to 30 µm thickness. PHBH-pellets from Kaneka are an example of a suitable reference material. This
information is given for the convenience of users of this document and does not constitute an endorsement by ISO
of the supplier named.
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oSIST prEN ISO 22766:2021
ISO 22766:2020(E)

— five frames for the negative reference material (F 1-5)
nR
The frames shall be marked by appropriate means to ensure a clear and permanent allocation of each
sample even after an exposure period of three years (see Figure 2).
Figure 2 — Code identifying that the sample is attached with a cable tie to the frame
The same number of replicates is requested if other forms than film, e.g. formed articles such as foams
or plates, are tested.
The above outlined number of replicates is sufficient for the determination of the disintegration at the
end of the exposure period after three years. Prepare the same number of replicates per sampling if
samples with exposure periods below or beyond three years are planned, e.g. to better characterize the
disintegration of a plastic material over time.
As this is a field test in different marine habitats, mechanical damage of test samples fixed between
two plastic frames and protected by a 2 mm × 2 mm protection mesh cannot be excluded during the
exposure period, possibly due to the erosive power of tides and sediment and activity of animals. Hence,
it is recommended to increase the number of replicates for each material to compensate any loss of test
specimens.
5.5 Exposure to marine habitats
The exposure of test specimens (see 5.3) to the seawater — seafloor interface at the sublittoral zone
shall be performed according to the procedure described in Annex A.
The exposure of test specimens (see 5.3) to the eulittoral zone shall be performed according to one of
the two procedures described in Annex B.
5.6 Termination of the field test
The disintegration is determined and reported after an exposure period of three years.
If test results from samples with exposure periods below three years are available revealing that no
more than 10 % of the original mass (dw) of the exposed surface area (see Figure 1) remains in the
oversize fraction after sieving through a 2 mm sieve (see 6.2), then the field test can be terminated before
the three-year exposure period has been reached and the degree of disintegration can be determined.
This also applies if the disintegration is determined by means of image analysis (photogrammetry) and
more than 90 % of exposed surface area is lost.
Samples are carefully removed from the eulittoral and the sublittoral zone, rinsed in ambient seawater
from the same exposure site, packed singly in zip-lock bags under wet conditions using the seawater
from the same exposure site and stored in sealed containers for the transportation to the laboratory.
After delivery, conserve the samples at low temperature (approximately 4 °C) until processing. It is
recommended that the samples are analysed within 2 days after sampling. Record storage time and
conditions.
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ISO 22766:2020(E)

6 Analysis and monitoring of the field test
6.1 Photographic documentation
The state and appearance of each replicate is documented by means of photographs at the beginning
and the end of the field test.
NOTE Photographs can be used for documentation purposes and rating of the extent of biofouling.
6.2 Determination of disintegration
6.2.1 General
The degree of disintegration is determined either by means of a sieving procedure (see 6.2.2) or by
means of image analysis (photogrammetry) (see 6.2.3).
Each test sample including the plastic frame and the 2 mm × 2 mm protection mesh is carefully checked
for any possible mechanical damage. If mechanical damage is observed, in particular with the 2 × 2 mm
protection mesh, the sample shall be discarded and not used for the determination of the disintegration.
6.2.2 Sieving procedure
6.2.2.1 General
Screen the samples for residual particles of the test material as follows.
If test specimen of 260 mm × 200 mm in size fixed between two non-degradable plastic frames have
been used (see 5.3) in the field test, then the following procedure applies: it is recommended that the
two plastic frames are not disassembled, as the part of a test specimen which is fixed between the two
plastic frames and that was not directly exposed to seawater, is not considered in the calculation of the
disintegration. The material of the exposure area including the meshes is quantitatively removed from
the plastic frame by appropriate means, e.g. using a razor blade or applying any other suitable method.
2
This procedure is not necessary if film specimen of 200 mm × 160 mm in size (surface area 320 cm )
not fixed between two non-degradable plastic frames (see 5.3) have been used.
Carefully remove the 2 mm × 2 mm protection meshes and collect all visible plastic material attached
to them.
Use sieves of suitable shape with screens of 2 mm and 10 mm mesh (as specified for instance in
ISO 3310-2).
To exclude major errors adhering particles and/or fouling organisms shall be carefully removed from
the remaining specimen material. If biofouling has been observed, sieve each of the samples through
a standard 10 mm sieve, search the overflow carefully for particles in which pieces of test material
remain. If necessary, break these up and collect the plastic material. Separate the sieved material
further by sieving through a standard 2 mm sieve. From the 2 mm to 10 mm fraction thus obtained,
pick out all particles of the test material, place them on a separate 2 mm sieve and clean carefully, if
possible by washing them under running deionized water. Dry the cleaned particles at 105 °C (or at
40 °C for test materials with melting temperatures below 105 °C) until constant mass is reached. The
mass of the test material not exposed to marine habitats is determined using film of 200 mm × 160 mm
2
in size which corresponds to 320 cm . From the mass of total dry solids thus obtained, calculate the
degree of disintegration as indicated in 6.2.2.2.
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ISO 22766:2020(E)

6.2.2.2 Calculating degree of disintegration
Add up the mass of the retrieved test material particles of all selected > 2 mm fractions (see 6.2.2.1)
and compare it to the mass of the initial test material input (see 6.2.2.1). Calculate the degree of
disintegration of the material, D , on the basis of the respective total dry solids using Formula (1):
i
mm−
12
D = ×100 (1)
i
m
1
where
D is the degree of disintegration of the test material, expressed in per cent (%);
i
m is the mass of total dry solids in the test material input, expressed in grams (g);
1
m is the mass of total dry solids in the retrieved test material, expressed in grams (g).
2
NOTE 1 D is, in practice, a measurement of mass loss where the lost mass is represented by all particles with
i
dimensions < 2 mm. As such it can also be referred as mass loss percentage.
NOTE 2 The disintegration of plastic materials can be underestimated if small proportion of a biofilm
(biofouling) cannot be completely removed from plastic debris.
6.2.3 Image analysis (photogrammetry)
6.2.3.1 General
The test specimen is secured bet
...