Table 4.

List of past and current method development exercises and proficiency tests for the analysis of microplastics in simple and complex matrices including current work being developed under OCPP.

Description	Organisers	Round number	Year	Particle type	Targeted matrices	Link/reference to report/output	Link to website
An interlaboratory comparison exercise for the determination of microplastics in standard sample bottles	Ministry of the Environment, Japan	–	2019	Microplastics (0.4–5.7 mm)	Seawater	50
Microplastics analysis development exercise	Quasimeme/NORMAN	1	2019	-Pre-production pellets -Microplastics	-Tablets with plastic particles	45	https://www.wepal.nl/en/wepal/Home/Proficiency-tests.htm
Microplastics analysis development exercise	Quasimeme/NORMAN	2	2020	Microplastics	-Tablets with plastic particles -Fish -Sediment	Report circulated	https://www.wepal.nl/en/wepal/Home/Proficiency-tests.htm
Microplastics analysis development exercise	Quasimeme/NORMAN in collaboration with the EU project EUROqCHARM	3	2022	Microplastics	Water, sediment	–	https://www.euroqcharm.eu www.quasimeme.org)
Proficiency test	JRC/BAM	–	2020	Microplastics	Water	Outputs of the exercise will be covered during a symposium: “Challenges of microplastic analysis—Bridging state of the art and policy needs” in September 2021	https://ec.europa.eu/jrc/en/news/finding-right-methods-measuring-microplastics-water
Project Missouri	–	–	–	–	Soil	Report circulated	https://www.ineris.fr/en/ineris/news/microplastics-ineris-leads-european-missouri-project
Norman Network	Joint Programme of Activities 2023	–	2023	WG-4 Sandwich Filters for the Comparison of Microplastic Measurements	Filters	–	WELCOME TO THE NORMAN NETWORK | NORMAN (norman-network.net)
Interlaboratory proficiency test on the use of Nile red for microplastic reporting	Cefas/UEA with support from EUROqCHARM	1	Planned for 2024	-Pre-production pellets -Microplastics	Water	Tablets with plastic particles	N/A

In bold: Planned activities under OCPP.