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Towards reliable measurement of microplastics in water

The JRC and BAM organised an interlaboratory comparison study on how to measure microplastics in water
Nov 16 2021

More harmonisation of analytical methods for microplastic quantification in water is needed to obtain reliable and comparable data, according to an inter-laboratory comparison study organised by the JRC.

Microplastics and possibly also nanoplastics are becoming widely spread throughout the environment. There is a lack of harmonised analytical measurement procedures (including sampling) and quality assurance tools such as validated methods with known performance and reference materials. This complicates the generation of reliable and comparable data.

The study and its follow-up

The JRC organised an interlaboratory comparison (ILC) study in cooperation with BAM (Bundesanstalt für Materialforschung und -prüfung, Germany). It investigated the state of the art of methods used for the analysis of microplastics in water. The study should also support the development of reference materials for microplastics.

Following an open call, nearly 100 laboratories in the EU and across the globe took part to it. The study started in February 2020 with the distribution of the test samples to the registered laboratories. The participants provided measurement results for characterised samples.  They also replied to a comprehensive questionnaire about detailed laboratory practices and analysis conditions. In total, 98 complete datasets were available for evaluation.

Recently, the JRC issued the final study report describing the design, execution and outcome of the exercise. In order to put the study’s results into policy context, a symposium “Challenges of microplastic analysis – Bridging the state of the art and policy needs” was organised in September 2021, attracting about 500 participants from EU countries and beyond. During the symposium, the outcome of the JRC/BAM study was presented, together with several other large ILC studies. Furthermore, representatives of the European Commission’s DG Environment and the State of California Water Board (USA) talked about the needs for policy and integration of harmonised/standardised methods in the regulatory process.

Need for harmonisation and standardisation

Discussions at the symposium highlighted the technical challenges in providing sound and robust results for the content of microplastics, even in neat water. Questions and ideas shared by participants emphasised the importance of interaction between standardisation bodies and the different actors developing methods, organising further ILC studies, and developing reference materials.

It also became clear that harmonisation/standardisation is not only needed for the analytical methods but also for the definition of the measurands (what is "microplastic"?), as well as contamination prevention and quality control.

Read the full report

Belz, S. et al., “Current status of the quantification of microplastics in water - Results of a JRC/BAM inter-laboratory comparison study on PET in water”, EUR 30799 EN, Publications Office of the European Union, Luxembourg, 2021, ISBN 978-92-76-40958-8, doi:10.2760/6228