ISO 16094-2

Water quality — Analysis of microplastic in water — Part 2: Vibrational spectroscopy methods for waters with low content of suspended solids including drinking water

This document specifies a method for the qualitative and quantitative analysis of microparticles of plastic or elastomeric materials in water using a microscopy technique coupled with vibrational spectroscopy. The aim is to generate reliable and comparable data on the potential presence of microplastics in clean waters with micro-Fourier transform infrared spectroscopy (μFTIR) and micro-Raman spectroscopy. For simplification, the addressed materials will be named "microplastics" in the document. The method allows: • Determination of the size distribution of microplastics (1 μm to 5 000 µm); • Identification of the composition of microplastics by characterizing, the type of polymer (PE, PP, PET, PTFE, PS, PVC, PC, PMMA, elastomers … The method is applicable to: • Ultrapure water in accordance with ISO 3696; • Water intended for human consumption (drinking water); • Bottled water; • Untreated groundwater.

Qualité de l'eau — Analyse des microplastiques dans l'eau — Partie 2: Méthodes de spectroscopie vibrationnelle pour les eaux à faible teneur en matières en suspension, y compris l'eau potable

General Information

• Status: Not Published
• ICS: 13.060.45 - Examination of water in general
• Technical Committee: ISO/TC 147/SC 2 - Physical, chemical and biochemical methods
• Drafting Committee: ISO/TC 147/SC 2 - Physical, chemical and biochemical methods
• Current Stage: 6000 - International Standard under publication
• Start Date: 14-Aug-2025
• Completion Date: 16-Aug-2025

Relations

• Consolidates: ISO/IEC 30190:2016/Amd 1:2019 - Information technology — Digitally recorded media for information interchange and storage — 120 mm Single Layer (25,0 Gbytes per disk) and Dual Layer (50,0 Gbytes per disk) BD Recordable disk — Amendment 1
• Effective Date: 20-Aug-2022

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/FDIS 16094-2
ISO/TC 147/SC 2
Water quality — Analysis of
Secretariat: DIN
microplastic in water —
Voting begins on:
2025-06-18
Part 2:
Vibrational spectroscopy methods
Voting terminates on:
2025-08-13
for waters with low content
of suspended solids including
drinking water
Qualité de l'eau — Analyse des microplastiques dans l'eau —
Partie 2: Méthodes de spectroscopie vibrationnelle pour les eaux
à faible teneur en matières en suspension, y compris l'eau potable
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 SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/CEN PARALLEL PROCESSING 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.
Reference number
ISO/FDIS 16094-2:2025(en) © ISO 2025

FINAL DRAFT
ISO/FDIS 16094-2:2025(en)
International
Standard
ISO/FDIS 16094-2
ISO/TC 147/SC 2
Water quality — Analysis of
Secretariat: DIN
microplastic in water —
Voting begins on:
Part 2:
Vibrational spectroscopy methods
Voting terminates on:
for waters with low content
of suspended solids including
drinking water
Qualité de l'eau — Analyse des microplastiques dans l'eau —
Partie 2: Méthodes de spectroscopie vibrationnelle pour les eaux
à faible teneur en matières en suspension, y compris l'eau potable
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 SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/CEN PARALLEL PROCESSING
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
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 Reference number
ISO/FDIS 16094-2:2025(en) © ISO 2025

ii
ISO/FDIS 16094-2:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 2
3 Terms, definitions and abbreviations . 2
3.1 Terms and definitions .2
3.2 Abbreviations .3
4 Principle . 4
5 Interferences . 4
6 Reagents, consumables and reference materials . 4
6.1 General .4
6.2 Particle-free water of known quality .4
6.3 Surfactant solution .5
6.4 Ethanol .5
6.5 Plastic reference material . .5
6.6 Containers for filter storage .5
7 Precautions for the laboratory environment, equipment and materials . 5
7.1 Operating precautions linked to the laboratory environment .5
7.2 Equipment .5
7.2.1 General .5
7.2.2 Infrared (IR) apparatus coupled to microscope.5
7.2.3 Raman coupled to microscope .6
7.2.4 Filtration system .6
7.2.5 Characteristics of filters: type and sizes.7
7.3 Precautions and cleaning protocol for materials .7
7.4 Bottles or containers for sampling .7
8 Sampling . 8
9 Operating protocol . 8
9.1 Volume of test sample .8
9.2 Sample filtration protocol .8
9.3 Analytical control blanks .9
9.4 Adjustment and calibration of instruments .9
9.4.1 Infrared microscope .9
9.4.2 Raman microscope .9
9.5 Cartesian coordinates of analysed particles.10
9.6 Analysis of the filter surface .10
9.6.1 General .10
9.6.2 Choice of the optical objectives .10
9.6.3 Selection of particles to be analysed or choice of the analysed surface area.10
9.6.4 TOTAL Model .10
9.6.5 RANDOM Model.11
9.6.6 CAKE Model .11
9.6.7 SPIRAL or HELIX Model . 12
9.6.8 Particles enumeration and size description . 12
9.6.9 IR spectra acquisition and particle identification . 12
9.6.10 Raman spectral acquisition and particle identification . 13
9.7 Sampling and analytical control blank analysis . 13
9.8 Spectra treatment . 13
9.9 Criteria of chemical composition identification.14
9.10 Spectral interferences .14
9.10.1 General .14

iii
ISO/FDIS 16094-2:2025(en)
9.10.2 Pigments or dyes . 15
9.10.3 Polyamide versus natural proteins . 15
9.10.4 Polyethylene versus other molecules with long CH-chain . 15
10 Method characterization and verification .15
10.1 General . 15
10.2 Verification of the particle size measurement accuracy . 15
10.3 Verification of microplastics identification and classification at claimed size . 15
10.4 Determination of minimal HQI for automatic identification .16
10.5 Determination of the reporting limits of the method .16
10.6 Verification of microplastics recovery rate of the method .17
11 Quality check of analytical control blanks in test series . 17
12 Expression of results .
...

ISO/FDIS 16094-2:2025(E)
ISO/TC 147/SC 2
Secretariat: DIN
Date: 2025-06-04
Water quality — Analysis of microplasticsmicroplastic in water —
Part 2:
Vibrational spectroscopy methods for waters with low content of
suspended solids including drinking water
Qualité de l'eau — Analyse des microplastiques dans l'eau — Partie 2: Méthodes utilisant la spectroscopie
vibrationnelle pour les eaux à faible teneur en matières en suspension incluant les eaux potables
First edition
Date: 2025-03-12
Partie 2: Méthodes de spectroscopie vibrationnelle pour les eaux à faible teneur en matières en suspension, y
compris l'eau potable
FDIS stage
ISO/FDIS 16094-2:2025(Een)
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: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2025 – All rights reserved
ii
ISO/FDIS 16094-2:2025(Een)
Contents
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 2
3 Terms, definitions and abbreviations . 2
3.1 Terms and definitions . 2
3.2 Abbreviations . 4
4 Principle . 4
5 Interferences . 5
6 Reagents, consumables and reference materials . 5
6.1 General. 5
6.2 Particle-free water of known quality . 5
6.3 Surfactant solution . 6
6.4 Ethanol . 6
6.5 Plastic reference material . 6
6.6 Containers for filter storage. 6
7 Precautions for the laboratory environment, equipment and materials . 6
7.1 Operating precautions linked to the laboratory environment . 6
7.2 Equipment . 7
7.3 Precautions and cleaning protocol for materials . 9
7.4 Bottles or containers for sampling . 10
8 Sampling . 10
9 Operating protocol . 11
9.1 Volume of test sample . 11
9.2 Sample filtration protocol . 11
9.3 Analytical control blanks . 12
9.4 Adjustment and calibration of instruments . 12
9.5 Cartesian coordinates of analysed particles . 13
9.6 Analysis of the filter surface . 13
9.7 Sampling and analytical control blank analysis . 18
9.8 Spectra treatment . 19
9.9 Criteria of chemical composition identification . 19
9.10 Spectral interferences . 20
10 Method characterization and verification . 21
10.1 General. 21
10.2 Verification of the particle size measurement accuracy . 21
10.3 Verification of microplastics identification and classification at claimed size . 21
10.4 Determination of minimal HQI for automatic identification . 21
10.5 Determination of the reporting limits of the method . 22
10.6 Verification of microplastics recovery rate of the method . 23
11 Quality check of analytical control blanks in test series . 24
12 Expression of results . 24
iii
ISO/FDIS 16094-2:2025(Een)
13 Test report . 25
Annex A (informative) List of characteristic wavenumbers for the main polymers . 27
Annex B (informative) Creation of an internal spectral database . 31
Annex C (informative) Description of known interference during acquisition of spectral
fingerprint — Presence of pigments . 37
Annex D (informative) Description of known interference during acquisition of spectral
fingerprint — Interference between natural and synthetic polyamides (proteins and
polyamide 6-6) . 40
Annex E (informative) Description of a known interference during acquisition of a spectral
fingerprint – Interferences of molecules with long CH-chain . 44
Annex F (informative) Quantum Cascade Laser (QCL) IR microscopy . 53
Annex G (informative) Performance data . 54
Bibliography . 56

iv © ISO 2025 – All rights reserved
iv
ISO/FDIS 16094-2:2025(Een)
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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 147, Water quality, Subcommittee SC 2, Physical,
chemical and biochemical methods, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 230, Water analysis, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 16094 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO/FDIS 16094-2:2025(Een)
Introduction
Pollution linked to microplastics is recognized as a global phenomenon. The standardization of the sampling,
quantification and identification protocols is required to ensure reliability and comparability of the data
produced for health and environmental risk assessments.
Microplastics in water can be identified and quantified using various methodological approaches. Depending
on the measurement objectives, several complementary approaches shall be used to cover the full spectrum
of microplastics (size and chemical nature). Table 1Table 1 resumes the characteristics and the information
obtained with spectroscopic techniques.
Table 1 — Characteristics of the various analytical techniques and information obtained.
Characteristics and information
Raman micro spectroscopy Infrared micro spectroscopy
obtained
Type of sample Water filtrate residues
Chemical nature of the polymer Yes
Information provided by analytical
Functional groups
technique
Results expression Polymer type, number of particles, size of particles
Minimum measurable size range of
1 µm to 5 µm 20 µm
particles
Minimum mass subject to
Undefined
measurement after preparation
Consequences for the test sample
Non-destructive
after measurement
Main interferences Mineralmineral particles, coloured Mineralmineral particles, proteins,
particles, pigments, fluorescence, surface alterations by biofilms or
fatty acids, fatty amides, proteins, weathering, particles loaded with
surface alterations by biofilms or carbon black, presence of water,
weathering, carbohydrates, carbohydrates generated by microbes
generated by microbes
vi © ISO 2025 – All rights reserved
vi
DRAFT INTERNATIONAL STANDARD ISO/FDIS 16094-2:2025(E)

Water quality — Analysis of microplasticsmicroplastic in water — —
Part 2:
Vibrational spectroscopy methods for waters with low content of
natural suspended solids including drinking water
WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated w
...

PROJET FINAL
Norme
internationale
ISO/FDIS 16094-2
ISO/TC 147/SC 2
Qualité de l'eau — Analyse des
Secrétariat: DIN
microplastiques dans l'eau —
Début de vote:
2025-06-18
Partie 2:
Méthodes de spectroscopie
Vote clos le:
2025-08-13
vibrationnelle pour les eaux à faible
teneur en matières en suspension, y
compris l'eau potable
Water quality — Analysis of microplastic in water —
Part 2: Vibrational spectroscopy methods for waters with low
content of suspended solids including drinking water
LES DESTINATAIRES DU PRÉSENT PROJET SONT
INVITÉS À PRÉSENTER, AVEC LEURS OBSERVATIONS,
NOTIFICATION DES DROITS DE PROPRIÉTÉ DONT ILS
AURAIENT ÉVENTUELLEMENT CONNAISSANCE ET À
FOURNIR UNE DOCUMENTATION EXPLICATIVE.
OUTRE LE FAIT D’ÊTRE EXAMINÉS POUR
ÉTABLIR S’ILS SONT ACCEPTABLES À DES FINS
INDUSTRIELLES, TECHNOLOGIQUES ET COM-MERCIALES,
AINSI QUE DU POINT DE VUE DES UTILISATEURS, LES
PROJETS DE NORMES
TRAITEMENT PARALLÈLE ISO/CEN
INTERNATIONALES DOIVENT PARFOIS ÊTRE CONSIDÉRÉS
DU POINT DE VUE DE LEUR POSSI BILITÉ DE DEVENIR DES
NORMES POUVANT
SERVIR DE RÉFÉRENCE DANS LA RÉGLEMENTATION
NATIONALE.
Numéro de référence
ISO/FDIS 16094-2:2025(fr) © ISO 2025

PROJET FINAL
ISO/FDIS 16094-2:2025(fr)
Norme
internationale
ISO/FDIS 16094-2
ISO/TC 147/SC 2
Qualité de l'eau — Analyse des
Secrétariat: DIN
microplastiques dans l'eau —
Début de vote:
Partie 2: 2025-06-18
Méthodes de spectroscopie
Vote clos le:
2025-08-13
vibrationnelle pour les eaux à faible
teneur en matières en suspension, y
compris l'eau potable
Water quality — Analysis of microplastic in water —
Part 2: Vibrational spectroscopy methods for waters with low
content of suspended solids including drinking water
LES DESTINATAIRES DU PRÉSENT PROJET SONT
INVITÉS À PRÉSENTER, AVEC LEURS OBSERVATIONS,
NOTIFICATION DES DROITS DE PROPRIÉTÉ DONT ILS
AURAIENT ÉVENTUELLEMENT CONNAISSANCE ET À
FOURNIR UNE DOCUMENTATION EXPLICATIVE.
DOCUMENT PROTÉGÉ PAR COPYRIGHT
OUTRE LE FAIT D’ÊTRE EXAMINÉS POUR
ÉTABLIR S’ILS SONT ACCEPTABLES À DES FINS
© ISO 2025 INDUSTRIELLES, TECHNOLOGIQUES ET COM-MERCIALES,
AINSI QUE DU POINT DE VUE DES UTILISATEURS, LES
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
PROJETS DE NORMES
TRAITEMENT PARALLÈLE ISO/CEN
INTERNATIONALES DOIVENT PARFOIS ÊTRE CONSIDÉRÉS
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
DU POINT DE VUE DE LEUR POSSI BILITÉ DE DEVENIR DES
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
NORMES POUVANT
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
SERVIR DE RÉFÉRENCE DANS LA RÉGLEMENTATION
NATIONALE.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Genève
Tél.: [phone]
E-mail: [e-mail]
Web: www.iso.org
Publié en Suisse Numéro de référence
ISO/FDIS 16094-2:2025(fr) © ISO 2025

ii
ISO/FDIS 16094-2:2025(fr)
Sommaire Page
Avant-propos .v
Introduction .vi
1 Domaine d'application . 1
2 Références normatives . 2
3 Termes, définitions et abréviations . 2
3.1 Termes et définitions .2
3.2 Abréviations.3
4 Principe. 4
5 Interférences . 4
6 Réactifs, consommables et matériaux de référence . 4
6.1 Généralités .4
6.2 Eau exempte de particules et de qualité reconnue .4
6.3 Solution de tensioactif .5
6.4 Éthanol .5
6.5 Matériau de référence de plastique .5
6.6 Récipients pour le stockage des filtres .5
7 Précautions relatives à l'environnement, aux équipements et aux matériaux du
laboratoire . 5
7.1 Précautions opérationnelles liées à l'environnement de laboratoire .5
7.2 Équipements .5
7.2.1 Généralités .5
7.2.2 Appareillage infrarouge (IR) couplé à un microscope .6
7.2.3 Appareillage Raman couplé à un microscope .6
7.2.4 Système de filtration .6
7.2.5 Caractéristiques des filtres: types et tailles .7
7.3 Précautions et protocole de nettoyage des matériels .8
7.4 Flacons ou récipients pour échantillonnage .8
8 Échantillonnage . 8
9 Protocole opératoire . 9
9.1 Volume de la prise d’essai de l'échantillon .9
9.2 Protocole de filtration d'échantillon .9
9.3 Blancs analytiques de contrôle .9
9.4 Réglage et étalonnage des instruments .10
9.4.1 Microscope infrarouge .10
9.4.2 Microscope Raman .10
9.5 Coordonnées cartésiennes des particules analysées .10
9.6 Analyse de la surface du filtre .11
9.6.1 Généralités .11
9.6.2 Choix des objectifs optiques .11
9.6.3 Sélection des particules à analyser ou choix de la surface analysée .11
9.6.4 Modèle TOTAL .11
9.6.5 Modèle ALÉATOIRE . 12
9.6.6 Modèle GÂTEAU . 12
9.6.7 Modèle SPIRALE ou HÉLIX . 13
9.6.8 Dénombrement des particules et description de leur taille . 13
9.6.9 Acquisition des spectres IR et identification des particules . 13
9.6.10 Acquisition spectrale Raman et identification des particules .14
9.7 Analyse des blancs d'échantillonnage et des blancs analytiques de contrôle .14
9.8 Traitement des spectres . 15
9.9 Critères d'identification de la composition chimique . 15
9.10 Interférences spectrales .16

iii
ISO/FDIS 16094-2:2025(fr)
9.10.1 Généralités .16
9.10.2 Pigments ou colorants .16
9.10.3 Polyamide par rapport aux protéines naturelles .16
9.10.4 Polyéthylène par rapport à d'autres molécules à longue chaîne de carbone .16
10 Caractérisation et vérification de la méthode .16
10.1 Généralités .16
10.2 Vérification de l'exactitude de la mesure de la taille des particules .16
10.3 Vérification de l'identification et de la classification des microplastiques à la taille
revendiquée .17
10.4 Détermination du HQI minimal pour l'identification automatique .17
10.5 Détermination de la limite de rapportage de la méthode .17
10.6 Vérification du taux de recouvrement des microplastiques de la méthode .18
11 Contrôle de la qualité des blancs analytiques de contrôle dans les séries d'essais .
...