oSIST prEN ISO 22766:2021

Plastics - Determination of the degree of disintegration of plastic materials in marine habitats under real field conditions (ISO 22766:2020)

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.

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)

Polimerni materiali - Ugotavljanje stopnje razpada polimernih materialov v morskih habitatih v realnih terenskih pogojih (ISO 22766:2020)

General Information

• Status: Not Published
• Public Enquiry End Date: 30-Sep-2021
• ICS: 13.020.40 - Pollution, pollution control and conservation
• ICS: 83.080.01 - Plastics in general
• Technical Committee: IPMA - Polimer materials and products
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 29-Jul-2021
• Due Date: 16-Dec-2021
• Completion Date: 25-Aug-2021
• Ref Project: prEN ISO 22766 - Plastics - Determination of the degree of disintegration of plastic materials in marine habitats under real field conditions (ISO 22766:2020)

Standards Content (sample)

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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
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

© ISO 2020 – All rights reserved iii
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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.
iv © ISO 2020 – All rights reserved
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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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oSIST prEN ISO 22766:2021
ISO 22766:2020(E)
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

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

habitats is 320 cm .

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)
— five frames for the positive reference material (F 1-5)

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)

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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oSIST prEN ISO 22766:2021
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.

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

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):

mm−
D = ×100 (1)
where

D is the degree of disintegration of the test material, expressed in per cent (%);

m is the mass of total dry solids in the test material input, expressed in grams (g);

m is the mass of total dry solids in the retrieved test material, expressed in grams (g).

NOTE 1 D is, in practice, a measurement of mass loss where the lost mass is represented by all particles with

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
...