Project Concensus - Establishing Traceable Concentration Measurements of Particles for a More Sustainable Industry

15/08/2025

Overview:
Engineered particle-based products can modernize the European healthcare, personal care, semiconductor, and energy sectors, driving a resilient, green, circular economy. However, there are no validated, standardised measurement methods for reliable quantification of number-based particle concentration or for the determination of the particle density and refractive index (RI), as essential input parameters for industry-standard methods. The ConcenSus project will deliver validated methods, modelling algorithms, documentary standards, and representative test materials to enable regulatory compliance and successful commercialisation of such products.

• Challenge
• Methods
• Objective
• Partners + Funding

Engineered particle-based products can modernize the European healthcare, personal care, semiconductor, and energy sectors and support a green, circular economy. However, there are no validated, standardised methods for the quantification of the number-based number concentration or for the determination of particle density and refractive index. The ConcenSus project will provide validated methods, modelling algorithms, documentary standards, and representative test materials to enable regulatory compliance and successful commercialisation of these products.

In this project material specific protocols for sample preparation for the measurement of particle number concentration will be developed and their performance evaluated in terms of accuracy, precision and traceability.
A new interlaboratory comparison (@VAMAS) on number concentration measurement of complex, industry-relevant particles in the size range from 1 nm to 1000 nm using different particle counting methods (e.g. spICP-MS, PTA, microscopy) and ensemble methods (e.g. SAXS, MADLS, CLS, UV-Vis, Raman spectroscopy), including sample preparation and distribution, measurement protocols and uniform data analysis and representation.

The project aims to improve metrological traceability and reduce uncertainty in number concentration measurements of relevant engineered particles in advanced materials and pollutants, by delivering validated, traceable, standardised approaches for the determination of density and refractive index.

Consortium: 5 Metrological Institutes (LGC, BAM, JSI, PTB and VSL), 6 external funded partners (CEA, ILOF, LUM, Postnova, TTK and UniPV) and 1 associated partner (Empa) from 9 European countries.

Coordination: Dr. Dorota Bartczak, LGC Limited (UK)

Funding: The project 24NRM02 ConcenSus has received funding from the European Partnership on Metrology, co-financed from the European Union’s Horizon Europe Research and Innovation Programme and by the Participating States.

Need:
Engineered particles play a key role in sustainable development and industry modernization. Robust number-based characterisation methods are needed for product innovation and to meet regulatory testing for healthcare and personal care (EU Regulations 745/2017, 749/2017, 1223/2009). Particulates, including micro- and nanoplastics, are also environmental and food pollutants, requiring reliable number-based measurement methods to support emerging regulations (e.g. drinking water Directive 21840/2020). Until now, standardised methods exist only for simple particles, while complex industry-relevant particles (e.g. lipid-based, hybrid, quantum dots) or environmental pollutants pose challenges, especially for ensemble methods, due to a lack of standardised input parameter characterisation (density and refractive index). Standard Developing Organisations, metrological bodies, and stakeholders express the need for validated, traceable, standardised methods featuring improved measurement uncertainty and modelling.

Objectives:
The project aims to improve metrological traceability and reduce uncertainty in number-concentration measurements of relevant engineered particles and pollutants, by delivering validated, traceable, standardised approaches for the determination of particle density and refractive index.

The specific objectives are

1. Develop at least three representative test materials (RTMs) which include industrially relevant or polluted particles, covering sizes (1 nm -1000 nm) and concentrations (10³–10¹⁴ g⁻¹), complete with characterised density and refractive index.
2. Assess and verify particle counting and ensemble methods (e.g. spICP-MS, PTA, SAXS, MADLS, CLS, UV-Vis, Raman spectroscopy) on RTMs. Develop new sample preparation protocols and run an interlaboratory comparison (ILC).
3. Develop traceable methods to reduce concentration measurement uncertainty to ^~20%. Define density and refractive index uncertainty requirements. Use a range of measurement techniques including TGA, CLS, XRD, FCM, UV-VIS, FFF-RI, and light scattering.
4. Validate in silico modelling for material parameters in measurement and develop a roadmap for traceability and standardisation of refractive index for particles.
5. Engage with standards bodies and users (CEN, ISO), contribute to revising and drafting standards, and initiate three new documentary standards on particle density and refractive index, and absolute number concentration by microscopy.

Coordinator

LGC Limited

Partner

JSI - Institut Jožef Stefan, Slovenia
PTB - Physikalisch-Technische Bundesanstalt, Germany
VSL - VSL B.V., Netherlands
CEA - Commissariat à l'énergie atomique et aux énergies alternatives, France
ILOF - INTELLIGENT LAB ON FIBER, UNIPESSOAL LDA, Portugal
LUM – LUM GmbH, Germany
Postnova - Postnova Analytics GmbH, Germany
TTK - Természettudományi Kutatóközpont, Hungary
UniPV - Università degli Studi di Pavia, Italy
Empa - Eidgenoessische Materialpruefungs- und Forschungsanstalt, Switzerland

Funding

The project 24NRM02 ConcenSus has received funding from the European Partnership on Metrology, co-financed from the European Union’s Horizon Europe Research and Innovation Programme and by the Participating States.