ISO 17088:2021

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 17088
ISO/TC 61/SC 14
Plastics — Organic recycling —
Secretariat: DIN
Specifications for compostable
Voting begins on:
2021­01­28 plastics
Voting terminates on:
Plastiques — Recyclage organique — Spécifications pour les
2021­03­25
plastiques compostables
RECIPIENTS OF THIS DRAFT ARE INVITED TO
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OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 17088:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2021

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ISO/FDIS 17088:2021(E)

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© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ISO/FDIS 17088:2021(E)

Contents Page
Foreword .iv
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 General . 4
5 Basic requirements . 4
5.1 General . 4
5.2 Disintegration during composting . 4
5.3 Ultimate aerobic biodegradability . 4
5.4 No adverse effect of compost on terrestrial organisms . 4
5.5 Control of constituents . 5
6 Detailed requirements . 5
6.1 General . 5
6.2 Disintegration during composting . 5
6.2.1 General. 5
6.2.2 Variation in permitted thickness . 6
6.3 Ultimate biodegradation . 6
6.3.1 Aerobic biodegradation . 6
6.3.2 Potential for biogas production . 7
6.4 No adverse effects of compost on terrestrial organisms . 8
6.4.1 General. 8
6.4.2 Ecotoxicity test scheme . 8
6.4.3 Plant growth test (mandatory) . 8
6.4.4 Acute earthworm toxicity test (mandatory) . 9
6.4.5 Chronic earthworm toxicity test (mandatory) . 9
6.4.6 Nitrification inhibition test with soil microorganisms (optional) . 9
6.5 Control of constituents . 9
6.5.1 General. 9
6.5.2 Regulated metals and other elements . 9
6.5.3 Per- and poly-fluorinated compounds (PFCs) .10
6.5.4 Other hazardous substances .10
6.5.5 Volatile solids .10
7 Declaration of results .10
8 Test report .10
Annex A (informative) Examples of maximum concentrations of regulated metals and other
elements .12
Annex B (normative) Detection of per- and poly-fluorinated substances compounds and
maximum concentrations other hazardous substances .13
Annex C (normative) Determination of ecotoxic effects on higher plants .14
Annex D (normative) Determination of acute ecotoxic effects to earthworm .16
Annex E (normative) Determination of chronic ecotoxic effects to earthworm .18
Annex F (informative) Determination of nitrification activity of soil microorganisms .20
Bibliography .22
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ISO/FDIS 17088:2021(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 non­governmental, 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.
This third edition cancels and replaces the second edition (ISO 17088:2012), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— in Clause 3:
— the following terms have been added: organic recycling, anaerobic digestion, per- and poly-
fluorinated compound, well-managed industrial composting process, industrial composting,
organic constituents, home composting;
— the term catalyst has been deleted;
— 6.1.4 has been deleted;
— a new subclause, 6.2.2, on variation in permitted thickness has been added;
— in 6.3, requirements regarding biodegradability of constituents have been revised;
— in 6.3.1.1, the following references have been added as additional laboratory test methods for
biodegradation testing: ISO 14851, ISO 14852, ISO 17556;
— a new subclause, 6.3.2, on potential for biogas production has been added;
— 6.4 has been extended covering ecotoxicity tests with representative species from three trophic levels;
— in 6.5, new requirements regarding control of constituents with respect to per- and poly-fluorinated
compounds (PFCs) and hazardous substances (as specified in Annex B) have been included;
— the list of regulated metals in EU + EFTA countries has been revised;
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ISO/FDIS 17088:2021(E)

— new annexes, Annex B, Annex C, Annex E and Annex F, have been added.
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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ISO/FDIS 17088:2021(E)

Introduction
Management of solid wastes is a problem of growing interest around the world. Cities, towns and
countries are attempting to divert more materials from disposal (landfills and incineration without
energy recovery) by performing different recovery options in order to transform waste into usable
products. Plastics recovery technologies include material recovery (mechanical recycling, chemical
or feedstock recycling, and biological or organic recycling) and the recovery of energy in the form of
usable heat under controlled combustion conditions.
This document intends to correctly identify compostable plastics, and compostable products made
from plastics, which can be recovered by organic recycling, i.e. will disintegrate and biodegrade
satisfactorily together with biowaste producing compost as an outcome, in composting or in anaerobic
digestion followed by composting, and will not leave any persistent or hazardous residues.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 17088:2021(E)
Plastics — Organic recycling — Specifications for
compostable plastics
WARNING — Sewage, activated sludge, soil and compost might contain potentially pathogenic
organisms. Therefore, appropriate precautions should be taken when handling them. Toxic test,
compounds and those whose properties are unknown should be handled with care.
1 Scope
This document specifies procedures and requirements for plastics, and products made from plastics,
that are suitable for recovery through organic recycling. The four following aspects are addressed:
a) disintegration during composting;
b) ultimate aerobic biodegradation;
c) no adverse effects of compost on terrestrial organisms;
d) control of constituents.
These four aspects are suitable to assess the effects on the industrial composting process.
This document is intended to be used as the basis for systems of labelling and claims for compostable
plastics materials and products.
This document does not provide information on requirements for the biodegradability of plastics which
end up in the environment as litter. It is also not applicable to biological treatment undertaken in small
installations by householders.
NOTE 1 The recovery of compostable plastics through composting can be carried out under the conditions
found in well­managed industrial composting processes, where the temperature, water content, aerobic
conditions, carbon/nitrogen ratio and processing conditions are optimized. Such conditions are generally
obtained in industrial and municipal composting plants. Under these conditions, compostable plastics
disintegrate and biodegrade at rates comparable to yard trimmings, kraft paper bags and food scraps.
NOTE 2 “Compostable” or “compostable in municipal and industrial composting facilities” are expressions
considered to be equivalent to organically recyclable for the purposes of this document.
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 472, Plastics — Vocabulary
ISO 11268­1, Soil quality — Effects of pollutants on earthworms — Part 1: Determination of acute toxicity
to Eisenia fetida/Eisenia andrei
ISO 11268­2, Soil quality — Effects of pollutants on earthworms — Part 2: Determination of effects on
reproduction of Eisenia fetida/Eisenia andrei
ISO 11269­2, Soil quality — Determination of the effects of pollutants on soil flora — Part 2: Effects of
contaminated soil on the emergence and early growth of higher plants
ISO 14851, Determination of the ultimate aerobic biodegradability of plastic materials in an aqueous
medium — Method by measuring the oxygen demand in a closed respirometer
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ISO/FDIS 17088:2021(E)

ISO 14852, Determination of the ultimate aerobic biodegradability of plastic materials in an aqueous
medium — Method by analysis of evolved carbon dioxide
ISO 14855­1, Determination of the ultimate aerobic biodegradability of plastic materials under controlled
composting conditions — Method by analysis of evolved carbon dioxide — Part 1: General method
ISO 14855­2, Determination of the ultimate aerobic biodegradability of plastic materials under controlled
composting conditions — Method by analysis of evolved carbon dioxide — Part 2: Gravimetric measurement
of carbon dioxide evolved in a laboratory-scale test
ISO 15685, Soil quality — Determination of  potential nitrification and inhibition of nitrification — Rapid
test by ammonium oxidation
ISO 16929, Plastics — Determination of the degree of disintegration of plastic materials under defined
composting conditions in a pilot-scale test
ISO 17556, Plastics — Determination of the ultimate aerobic biodegradability of plastic materials in soil by
measuring the oxygen demand in a respirometer or the amount of carbon dioxide evolved
EN 14582, Characterization of waste — Halogen and sulfur content — Oxygen combustion in closed
systems and determination methods
OECD 2006), Test No. 208: Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test, OECD
Guidelines for the Testing of Chemicals, Section 2, OECD Publishing, Paris,
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 and the following 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
compost
organic soil conditioner obtained by biodegradation of a mixture consisting principally of vegetable
residues, occasionally with other organic material and having a limited mineral content
[SOURCE: ISO 472:2013, 2.1735]
3.2
compostable plastic
plastic that undergoes degradation by biological processes during composting to yield CO , water,
2
inorganic compounds and biomass at a rate consistent with other known compostable materials and
leave no visible, distinguishable or toxic residue
Note 1 to entry: "Hazardous" is used synonymously to "toxic".
3.3
composting
aerobic process designed to produce compost starting from biodegradable waste
Note 1 to entry: Composting is classified into industrial composting, home composting and worm composting.
3.4
disintegration
physical breakdown of a material into very small fragments
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ISO/FDIS 17088:2021(E)

3.5
filler
relatively inert solid material added to a plastic to modify its strength, permanence, working properties
or other qualities, or to lower costs
3.6
organic recycling
aerobic (composting) or anaerobic (digestion) treatment of plastics waste under controlled conditions
using micro-organisms to produce, in the presence of oxygen, stabilized organic residues (compost),
carbon dioxide and water or, in the absence of oxygen, stabilized organic residues (compost), methane
and carbon dioxide
Note 1 to entry: The term “biological recycling” is used synonymously.
[SOURCE: ISO 15270:2008, 3.5, modified — "biodegradable" has been omitted and "(compost)" has
been added.]
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
3.8
ultimate aerobic biodegradation
breakdown of an organic compound by microorganisms in the presence of oxygen into carbon dioxide,
water and mineral salts of any other elements present (mineralization) plus new biomass
3.9
volatile solid
solids obtained by subtracting the residue of a known volume of test material or compost after
incineration at about 550 °C from the total dry solids (3.7) of the same sample
Note 1 to entry: The volatile-solids content is an indication of the amount of organic matter present.
3.10
anaerobic digestion
process of controlled decomposition of biodegradable materials under managed conditions where free
oxygen is absent, at temperatures suitable for naturally occurring mesophilic or thermophilic anaerobic
and facultative bacteria species, that convert the inputs to a methane rich biogas and digestate
Note 1 to entry: In a second phase, the digestate is typically stabilised by means of a composting (aerobic) process.
3.11
per- and poly-fluorinated compound
PFC
organofluorine compound containing only carbon-fluorine bonds and carbon-carbon bonds but also
other heteroatoms
3.12
well-managed industrial composting process
composting process performed under controlled conditions where the temperature, water content,
aerobic conditions, carbon/ nitrogen ratio and other conditions are optimized
3.13
industrial composting
composting process performed under controlled conditions on industrial scale with the aim of
producing compost for the market
Note 1 to entry: In some regions industrial composting is referred to as professional composting.
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ISO/FDIS 17088:2021(E)

3.14
organic constituent
chemical constituent that contains carbon covalently linked to other carbon atoms and to other
elements, most commonly hydrogen, oxygen or nitrogen
Note 1 to entry: Inorganic carbonates, carbides, cyanides and simple oxides such as carbon monoxide and carbon
dioxide are not considered as organic constituent.
Note 2 to entry: Allotropes of carbon, such as diamond, graphite, carbon black, fullerenes, and carbon nanotubes
are also not considered as organic constituent.
3.15
home composting
practice performed by a private individual with the aim of producing compost for his own use
4 General
4.1 The purpose of this document is to establish requirements for plastics materials and plastics
products that can be recovered by means of organic recycling in well-managed industrial composting
facilities where the typical conditions of composting can be consistently obtained (i.e. a long thermophilic
phase, aerobic conditions, sufficient water content, a suitable carbon/nitrogen ratio, etc.).
4.2 The following characteristics are determined:
a) the ultimate level of aerobic biodegradation of the test material;
b) the degree of disintegration obtained;
c) any negative effects on the finished compost;
d) the maximum concentration of regulated metals and other elements and per- and poly-fluorinated
compounds (PFCs) (determined as fluorine) in the test material.
In addition, the use of other hazardous substances as specified in Annex B in the test material is
assessed.
5 Basic requirements
5.1 General
In order to comply with this document, plastics products and materials shall demonstrate each of the
characteristics found in 5.2 to 5.5, as quantified in Clause 6.
5.2 Disintegration during composting
The plastics product or material shall disintegrate during composting as quantified in 6.2.
5.3 Ultimate aerobic biodegradability
The ultimate level of aerobic biodegradation shall be established by testing under controlled conditions
as quantified in 6.3.
5.4 No adverse effect of compost on terrestrial organisms
The composting of plastics products or materials shall have no adverse effects on terrestrial organisms
as quantified in 6.4.
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ISO/FDIS 17088:2021(E)

Ecotoxic effects on terrestrial organisms shall be determined by comparing compost produced with
and without the addition of a plastics product or a material.
5.5 Control of constituents
The plastics product or material under investigation shall be identified and characterized prior to
testing including:
— determination of the presence of regulated metals and other elements;
— determination of the presence per- and poly-fluorinated compounds (PFCs) (determined as fluorine);
— evaluation of the presence of other hazardous substances as specified in Annex B;
— determination of volatile solids;
as quantified in 6.5, taking legal compliance into consideration.
6 Detailed requirements
6.1 General
6.1.1 In order to be identified as compostable, products and materials shall meet the requirements
of 6.2, 6.3, 6.4 and 6.5, using appropriate laboratory tests representative of the conditions found in
industrial composting facilities.
6.1.2 Test samples shall not be subjected to conditions or procedures designed to accelerate
disintegration or biodegradation prior to testing as described in 6.2 or 6.3.
6.1.3 If the products or materials under test include inorganic fillers, the fillers shall be present when
the products or materials are tested as described in 6.2, 6.3, 6.4, 6.5.2 and 6.5.3. However, their inorganic
carbon content shall be excluded from the mineralization calculations in 6.3. Products or materials
to which fillers are subsequently added, or in which the filler content is changed, shall be retested to
demonstrate that the new material meets the requirements of 6.2, 6.3, 6.4, 6.5.2 and 6.5.3. Manufacturers
may establish an acceptable range by testing the highest and the lowest concentrations. In addition,
fillers shall be identified and assessed according to 6.5.4 with respect to potential hazardous properties
as defined in Annex B. Examples of inorganic fillers include (but are not limited to) calcium carbonate
and titanium dioxide.
An exception shall be made for materials containing calcium carbonate or other carbonates as a filler.
For biodegradation, these materials should be tested without the carbonate filler as this might disturb
an exact measurement. For chemical analyses, disintegration and toxicity the material should however
be tested with the carbonate filler included.
6.2 Disintegration during composting
6.2.1 General
When testing finished articles and products, testing shall be conducted starting with the articles and
products in the same form as they are intended to be used. For products and materials that are made in
several different thicknesses or densities, such as films, containers and foams, only the thickest or most
dense products and materials need to be tested as long as the chemical composition and structure of
the respective articles and products remain the same.
NOTE 1 In general, for practical reasons, samples of the plastic material are tested in order to define the
maximum thickness allowing disintegration. Finished articles and products are then manufactured with
thicknesses below the maximum thickness.
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ISO/FDIS 17088:2021(E)

A plastics product is considered to have demonstrated satisfactory disintegration if, after 84 days in a
controlled composting test, it is completely disintegrated into less than 2 mm fragments. This is proven
if no more than 10 % of its original dry mass remains after sieving through a 2,0 mm sieve.
NOTE 2 The 90 % threshold is the result of complete disintegration (100 %) minus 10 % tolerance. A 10 %
tolerance is applied in order to take into consideration the variability occurring in biological processes.
The test shall be carried out in accordance with ISO 16929.
Alternatively, the lab-scale test in accordance with ISO 20200 can be used. The initial test item
concentration shall be 1 % (wet mass) in each of these tests following the procedure given in ISO 16929.
In case of differing results, ISO 16929 results shall prevail.
Special attention should be given to the visual aspects of compost. Visual contamination of compost
as evidenced by reduction of aesthetic acceptability should not be significantly increased by any post
composting residues of the introduced plastics product or material. Therefore, any residue shall be
indistinguishable to the naked eye from the other matter in the compost at a distance of 500 mm. The
visible assessment of the compost shall be documented by means of photography.
6.2.2 Variation in permitted thickness
In some cases, specific composting technologies require early sieving and fast disintegration. In this
case, the following rule shall apply in order to identify the maximum thickness.
If disintegration is achieved for the maximum thickness (X) in 12 weeks, it shall be deemed given that
a thickness of X x
...