oSIST prEN ISO 24187:2022

Principles for the analysis of plastics and microplastics present in the environment (ISO/DIS 24187:2021)

Development of technical principles, which will be used across the board for future standardization
projects on testing methods for plastics and microplastics in various matrices (in particular water, soil,
compost, sewage sludge, biota). This includes the following::
- Description of necessary working conditions in the laboratory
- Description of necessary working conditions in the field
- safety instructions
- Proposals for harmonisation of size classes to be considered
- Proposals to harmonise the indication of results
- Notes on matrix-specific particularities with regard to the representativeness of the results

Grundsätze für die Analyse von Kunststoffen und Mikroplastik in der Umwelt (ISO/DIS 24187:2021)

Principes pour l'analyse des plastiques et des microplastiques présents dans l'environnement (ISO/DIS 24187:2021)

Načela za analizo plastike in mikroplastike v okolju (ISO/DIS 24187:2021)

General Information

• Status: Not Published
• Public Enquiry End Date: 28-Feb-2022
• ICS: 13.020.01 - Environment and environmental protection in general
• ICS: 83.080.01 - Plastics in general
• Technical Committee: IPMA - Polimer materials and products
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 15-Dec-2021
• Due Date: 04-May-2022
• Ref Project: prEN ISO 24187 - Principles for the analysis of plastics and microplastics present in the environment (ISO/DIS 24187:2021)

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 24187:2022
01-februar-2022
Načela za analizo plastike in mikroplastike v okolju (ISO/DIS 24187:2021)

Principles for the analysis of plastics and microplastics present in the environment

(ISO/DIS 24187:2021)

Grundsätze für die Analyse von Kunststoffen und Mikroplastik in der Umwelt (ISO/DIS

24187:2021)
Principes pour l'analyse des plastiques et des microplastiques présents dans
l'environnement (ISO/DIS 24187:2021)
Ta slovenski standard je istoveten z: prEN ISO 24187
ICS:
13.020.01 Okolje in varstvo okolja na Environment and
splošno environmental protection in
general
83.080.01 Polimerni materiali na Plastics in general
splošno
oSIST prEN ISO 24187:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO 24187:2022
---------------------- Page: 2 ----------------------
oSIST prEN ISO 24187:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 24187
ISO/TC 61/SC 14 Secretariat: DIN
Voting begins on: Voting terminates on:
2021-12-08 2022-03-02
Principles for the analysis of plastics and microplastics
present in the environment
ICS: 13.020.01; 83.080.01
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 24187:2021(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2021
---------------------- Page: 3 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

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]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
© ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 General Aspects ....................................................................................................................................................................................................3

5 General requirements for all analytical steps ..................................................................................................................... 4

6 Identification of appropriate detection methods ............................................................................................................. 5

6.1 General ........................................................................................................................................................................................................... 5

6.2 Classification of detection tools .............................................................................................................................................. 5

6.3 Identification of addressed objective ................................................................................................................................. 6

7 Sampling of water ............................................................................................................................................................................................... 6

7.1 General ........................................................................................................................................................................................................... 6

7.2 Sampling volume ................................................................................................................................................................................... 7

7.3 Mesh sizes ................................................................................................................................................................................................... 7

7.4 Filter materials ....................................................................................................................................................................................... 8

7.5 Sampling Devices.................................................................................................................................................................................. 8

8 Sampling of terrestric, semiterrestric and subhydric soils ................................................................................... 8

8.1 General aspects ...................................................................................................................................................................................... 8

8.2 Sampling of terrestrial soils ....................................................................................................................................................... 8

8.3 Sampling of semiterrestrial soils ........................................................................................................................................... 9

8.4 Sampling of subhydric soils (sediments) ......................................................................................................................... 9

9 Sampling of air ....................................................................................................................................................................................................... 9

9.1 Indoor Air .................................................................................................................................................................................................... 9

9.2 Outdoor Air ................................................................................................................................................................................................ 9

10 Sampling of sludges and other similar materials ............................................................................................................. 9

11 Sampling of mineral and other inorganic materials ..................................................................................................10

12 Sampling of biota ..............................................................................................................................................................................................10

13 Sample preparation .......................................................................................................................................................................................10

13.1 General aspects ................................................................................................................................................................................... 10

13.2 Drying .......................................................................................................................................................................................................... 11

13.3 Milling and grinding ....................................................................................................................................................................... 11

13.4 Removal of inorganic matter .................................................................................................................................................. 11

13.5 Removal of organic matter ....................................................................................................................................................... 11

14 Data Processing ...................................................................... ............................................................................................................................12

14.1 General Aspects ..................................................................................................................................................................................12

14.2 Single spectra / chromatogram interpretation .....................................................................................................12

14.3 Interpretation of large spectra / chromatogram data sets .........................................................................12

15 Aspects of analytical quality assurance ..................................................................................................................................13

15.1 Reference Materials ........................................................................................................................................................................13

15.2 Performance of interlaboratory comparison tests.............................................................................................. 14

Annex A (informative) Advanced Data Processing ............................................................................................................................16

Bibliography .............................................................................................................................................................................................................................22

iii
© ISO 2021 – All rights reserved
---------------------- Page: 5 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)
Foreword

123 – test 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.
© ISO 2021 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)
Introduction

The analysis of plastics and microplastics is a rather new field in relation to other areas of environmental

analysis. A large number of scientific publications exist, but they do not apply a uniform analysis, which

makes it difficult to compare the results.

The differences in the approaches start with very basic things, which are quite different from the

approach of conventional environmental analysis.

This standard sets out key principles for the investigation of microplastics in the environment, which

should be taken into account in the subsequent development of specific procedures for sampling,

sample preparation and detection. A large number of the principles described in this document could

be applied, analogously, to other matrices and products, including foodstuffs and drinking water. The

objective is to present a pool of methods and notes that is as harmonized as possible and to make it

available for use in science, businesses and administrations.

What is true for analytics is also true for definitions in the same way. On the one hand, the terms

used here are based on existing definitions in the subject area, but on the other hand, analytical

requirements are also taken into account. This applies, for example, to the terms “large microplastics”

and “small macroplastics”. The particle size to be investigated is closely related to the detection method

to be selected. In the course of future specific work, it will therefore probably be necessary to modify

existing definitions slightly and adapt them to new knowledge and requirements.

The definitions chosen in this document are adapted from the ISO report on plastics. The basis of the

classification is based on the metric sizes and the associated designations. Microplastics is thus derived

from micrometres.

NOTE Microplastics can also stem from different sources not specifically mentioned in this document, such

as textiles, paints and tyres.
© ISO 2021 – All rights reserved
---------------------- Page: 7 ----------------------
oSIST prEN ISO 24187:2022
---------------------- Page: 8 ----------------------
oSIST prEN ISO 24187:2022
DRAFT INTERNATIONAL STANDARD ISO/DIS 24187:2021(E)
Principles for the analysis of plastics and microplastics
present in the environment
1 Scope

This document describes the principles to be followed in the analysis of plastics in various

environmental matrices (plastics testing). This includes the unique particle size classification of plastics,

the use of certain apparatus with regard to sampling, sample preparation, and the determination of

representative sample quantities. The purpose of this standard is to specify minimum requirements

until specific standards for the different case situations are available. This is important to ensure that

the development of the specific standards is done on a consistent basis to ensure that comparison or

correlation of results is possible.
This standard does not include requirements for monitoring actions.
2 Normative references
There are no normative references in this document.
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 https:// www .electropedia .org/
3.1
analysis
sequence of sampling, sample preparation and detection

Note 1 to entry: Detection may include particle counting, determination of mass, particle sizing and identification

of chemical composition.
3.2
plastics

material which contains as an essential ingredient a high polymer and which, at some stage in its

processing into finished products, can be shaped by flow

Note 1 to entry: Plastics contains mainly polymers and minor contents of additives. In addition reinforcements

may be added in very variable amounts.

Note 2 to entry: Supplementary to the term “plastics”, “plastics product” is also used. According to ISO 472, a

plastics product represents “any material or combination of materials, semi-finished or finished product that is

within the scope of ISO/TC 61 “Plastics”.
Note 3 to entry: Plastics comprise both thermoplastics and thermoset materials.
Note 4 to entry: In the broader society discussion rubber is included.

[SOURCE: ISO/TR 21960:2020, 3.2, modified — term numbers in Notes to entry removed, Note 4 to

entry added.]
© ISO 2021 – All rights reserved
---------------------- Page: 9 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)
3.3
macroplastics

any solid plastics particle or object insoluble in water with dimension above 5 cm

Note 1 to entry: Typically, a macroplastics object represents an item consisting of plastics or a part of an end-user

product or a fragment of the respective item.

Note 2 to entry: The defined dimension is related to the longest length of the particle.

[SOURCE: ISO/TR 21960:2020, 3.8, modified — in Note 1 to entry, “for example cups, cup covers” was

deleted; In Note 2 to entry, “distance” was replaced by “length”.]
3.4
small macroplastics

any solid plastics particle or object insoluble in water with dimension between 5 mm and 5 cm

Note 1 to entry: Typically, a macroplastics object represents an item consisting of plastics or a part of an end-user

product or a fragment of the respective item.

Note 2 to entry: The defined dimension is related to the longest length of the particle.

3.5
large microplastics

any solid plastics particle insoluble in water with any dimension between 1 mm and 5 mm

Note 1 to entry: Microplastics may show various shapes.

Note 2 to entry: Typically, a large microplastics object represents an item consisting of plastics or a part of an

end-user product or a fragment of the respective item.

Note 3 to entry: Microplastics in this size range are, for example, plastics pellets as intermediates for further

down- stream processing such as moulding, extrusion etc. resulting to semi-finished products which are not

final end-user products.

[SOURCE: ISO/TR 21960:2020, 3.10, modified — term number in Note 1 to entry was removed,]

3.6
microplastics

any solid plastics particle insoluble in water with dimension between 1 µm and 1 000 µm (= 1 mm)

Note 1 to entry: Primary microplastics object represents a particle intentionally added to end-user products for

example cosmetic means, coatings, paints etc. Secondary microplastics object can also result as a fragment of the

respective item.

Note 2 to entry: Microplastics have regular and irregular shapes (see ISO 9276-6:2017) .

Note 3 to entry: The defined dimension is related to the longest length of the particle.

[SOURCE: ISO/TR 21960:2020, 3.9, modified — Note 1 to entry was removed, all other Notes to entry

were changed.]
3.7
nanoplastics
plastics particles smaller than 1 µm
Note 1 to entry: According to OECD and ISO 19430 nanoparticles are up to 100 nm.
[SOURCE: ISO/TR 21960:2020, 3.13]
3.8
degradation

any physical or chemical change in polymer as a result of environmental factors, such as light, heat,

moisture, chemical conditions or biological activity
© ISO 2021 – All rights reserved
---------------------- Page: 10 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)
3.9
particle
minute piece of matter with defined physical boundaries
[SOURCE: ISO 26824:2013, 1.1, modified — Notes to entry were removed.]
3.10
zero sample
sample taken before the start of a spiking test
3.11
blank sample

sample of a similar solid or liquid to the real sample excluding the objects to be investigated

3.12
state of degradation

state of a substance or material after influence of chemical, biological or physical processes, for example

hydrolysis, photolysis, reduction and oxidation
3.13
additives

chemicals added to polymers to improve/change the individual properties of the specific plastic

material

Note 1 to entry: Important additives such as fillers/reinforced materials, softeners and flame retardants are

referenced according to ISO 1043-2 to ISO 1043-4.
4 General Aspects

Microplastics is a term that comes along with different physical and chemical properties, such as

shape, size (range), type of polymer(s), presence of additives, presence of fillers, state of degradation

and so on. The amount of microplastics in a given matrix can be measured in different ways, i.e. as

number (of particles) or mass content/fraction in relation to the sample’s quantity, which itself can be

based on various units (volume, weight, etc.). Hence, before selecting a suitable (set of) method(s), the

question(s) to be answered and properties to be measured need to be defined carefully. This applies

not only to detection methods but also to the sampling and processing/preparation methods associated

with them, right up to the statistical evaluation of results. At the end of the document, an overview of

the strengths and limitations of different methods with regard to a given problem can be found. An

essential objective for the assessment of methods was the safe and comprehensible investigation of

the transport paths and entry points into various environmental media such as water and soil using

appropriate measurement and analytical methods.

A schematic representation of the interdependencies of microplastics analysis is shown in Figure 1. As

a rule, the objective or objectives of a measurement or a measurement program is/ are based on a clear

question/task or on an evaluation concept involving necessary assessment parameters, respectively

(for example integration into an overall ecological context, thresholds for monitoring). A suitable

detection method is then selected, which generates the desired result parameters (such as polymer

type, mass content, number, shape, size, degradation status).
© ISO 2021 – All rights reserved
---------------------- Page: 11 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)

Figure 1 — Schematic representation of interdependencies during microplastics analysis in

environmental and related matrices
5 General requirements for all analytical steps

All analytical steps (sampling, sample preparation, detection) shall be undertaken in plastics-free

or low-plastics working conditions. These include the avoidance of standard plastics products (for

example tubes, vessels). Cross-contamination shall be avoided, the user should avoid using plastics

equipment wherever possible. Instead, alternatives made of metal, glass or ceramics should be used. As

an exception types of plastics that are not to be detected or evaluated can be used as well. Care should

be taken that also personal protective equipment (e.g. lab coats, gloves) are made of non-synthetic

material or material that does not interfere with the analyses. Recovery tests should be performed for

each analytical step.

If feasible, samples should be handled in laminar flow boxes in the laboratory or clean rooms (class 3

according to ISO 14644-1, especially during the preparation process of samples and during the

determination of particle numbers.

It shall be determined beforehand, whether a hygienization of samples is necessary. Sterilization

is a standard recommendation for the analysis of dry samples from wastewater, sewage sludge and

organic wastes. Various methods can be applied, but each of them has specific impact on the integrity of

microplastics particles in the sample:
i. Steam sterilization: risk of melting microplastics (for example PE, PP)

ii. Radiation sterilization (gamma, beta radiation, UV radiation): risk that the polymer structure is

degraded (cleavage of polymer chains and oxidation)

iii. Chemical sterilization: risk that polymer structure or the particles’ surface is chemically modified

Relevant information about the measurement conditions and control processes (quality assessment

and quality control/QAQC) shall be recorded, including all analytical steps. For general quality control

measures in laboratories, see ISO/IEC 17025:2017. For intercomparison tests, see ISO 13528:2005.

The documentation and measurement of zero samples or blank value determination for the applied

detection methods is essential, since contamination (for example by airborne particles) during

sampling, preparation and detection can easily occur. Determination of blank values is necessary; the

number of blanks depends on the concrete method to be applied. More specific requirements have to be

given in upcoming standards.

A classification of microplastics analyses into size classes according to Table 1 is recommended. Small

particles that occur in higher quantities are grouped into narrower classification clusters than the

larger particles, which are more relevant in terms of mass and classified into wider clusters. This also

enables a higher methodological feasibility of processes (including feasibility of filtration, detection

limits in analytics) and a better integration of particle quantities/masses in impact analyses (i.e. for

© ISO 2021 – All rights reserved
---------------------- Page: 12 ----------------------
oSIST prEN ISO 24187:2022
ISO/DIS 24187:2021(E)

environmental assessments). The proposed size classes are given in Table 1. The maximum dimension/

diameter of a particle defines the size class.
Table 1 — Particle size classification
large mi-
classification microplastics
croplastics
particle size < 1 000 to < 500 to < 100 to
μm 5 000 to 1 000 < 50 to 10 < 10 to 5 < 5 to 1
classes 500 100 50
average parti-
μm 3 000 750 300 75 30 7,5 3
cle size
a −4 −5 −7 −8
mass mg 14 0,22 0,014 2,2 × 10 1,4 × 10 2,2 × 10 1,4 × 10
number of
4 6 7 9
particles in number 1 64 1 000 6,4 × 10 1,0 × 10 6,4 × 10 1,0 × 10
14,13 mg

Mass here is determined from the average particle size assuming spherical particle with a density of 1.

6 Identification of appropriate detection methods
6.1 General

The selection of one or more quantitative or qualitative detection methods depends specifically on

the objectives and tasks of a project or an existing requirement. The various detection methods differ

regarding the generated result per measurement. These include identification of the polymer (type of

polymer) and other qualitative properties (i.e. presence of additives, chemical composition, molecular

weight and morphology of particle surface, particle size and shape) and quantitative properties

(particle number, particle mass fraction).

Depending on the objective of the analysis, it can be sufficient to apply a (pre-)screening method that

may give limited information, but does not require sophisticated instrumentation. For (pre-)screening

purposes relatively simple and inexpensive techniques could be used which give some information.

Like this, cost-effective routine analyses could be carried out with a higher throughput than more

performant but highly time consuming and costly techniques.
6.2 Classification of detection tools

Different detection methods based on various measurement principles are available for microplastics

analysis.

Spectroscopic methods can capture and assign the characteristics of specific chemical structure

of polymers using reference spectra. Commonly used methods are based on Infrared Spectroscopy

techniques (including on microscopic level) including different measurement setups:

• Fourier Transform Infrared Spectroscopy (FTIR),

• Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR),

• Focal Plan Array Detector Fourier Transform Infrared Spectroscopy (FPA-FTIR),
• Quantum cascade laser induced infrared spectroscopy (QCL-IR),
• Near or Short-Wave Infrared Spectroscopy (NIR, SWIR).
Alternatively, Raman Spectroscopy can be used, also on the microscopic level.

In thermo-analytical methods, the sample is pyrolysed under inert conditions and specific

decomposition products of the individual polymers are detected. Currently well established are Gas

Chromatography-Mass Spectrometry (GC-MS) methods. They differ regarding the heating proce

...