Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability matters

Graphene-related materials (GRMs) are used in many innovative applications for their outstanding physico-chemical properties. Their possible release could have critical consequences for the environment. According to a European Union regulation, one of the test guidelines (TG) that must be applied to...

Full description

Saved in:
Bibliographic Details
Main Authors: Giada Caorsi, Fabio Candotto Carniel, Morgan Légnani, Emmanuel Flahaut, Viviana Jehová González, Ester Vázquez, Maurizio Prato, Mauro Tretiach
Format: Article
Language:English
Published: Elsevier 2025-03-01
Series:Ecotoxicology and Environmental Safety
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S0147651325002246
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850222496769376256
author Giada Caorsi
Fabio Candotto Carniel
Morgan Légnani
Emmanuel Flahaut
Viviana Jehová González
Ester Vázquez
Maurizio Prato
Mauro Tretiach
author_facet Giada Caorsi
Fabio Candotto Carniel
Morgan Légnani
Emmanuel Flahaut
Viviana Jehová González
Ester Vázquez
Maurizio Prato
Mauro Tretiach
author_sort Giada Caorsi
collection DOAJ
description Graphene-related materials (GRMs) are used in many innovative applications for their outstanding physico-chemical properties. Their possible release could have critical consequences for the environment. According to a European Union regulation, one of the test guidelines (TG) that must be applied to check the environmental hazard of new substances is the OECD TG 201 - Algae and Cyanobacteria Growth Inhibition Test. It was developed for water-soluble substances, whereas GRMs are not: dispersed in aqueous media, they tend to aggregate and settle, changing their bioavailability. This work aims to evaluate the applicability of the TG 201 to GRMs by investigating the stability of GRMs dispersions (GDS) in the TG 201 medium, focusing on the stability criterion of TG 201, i.e. maintaining ± 20 % of the nominal initial concentration. Based on flow-cytometry, Turbiscan and Utermöhl sedimentation chamber measurements, the following factors were tested: (i) particle composition and (ii) concentration; (iii) application of turbulence; (iv) addition of dispersants; (v) presence/absence of the target organism. Strong agglomeration/aggregation and sedimentation phenomena were observed for all materials under all tested conditions, thus the stability criterion of TG 201 was not met. Nevertheless, this can be satisfied by allowing an adequate period of time (approx. 6 h) for the GRM dispersion to stabilize after its preparation. Only then, a detailed physico-chemical characterization of the suspended material is required, which must be reiterated at the end of the test.
format Article
id doaj-art-8b60e1535aed4233bc010c65c189e98a
institution OA Journals
issn 0147-6513
language English
publishDate 2025-03-01
publisher Elsevier
record_format Article
series Ecotoxicology and Environmental Safety
spelling doaj-art-8b60e1535aed4233bc010c65c189e98a2025-08-20T02:06:19ZengElsevierEcotoxicology and Environmental Safety0147-65132025-03-0129211788810.1016/j.ecoenv.2025.117888Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability mattersGiada Caorsi0Fabio Candotto Carniel1Morgan Légnani2Emmanuel Flahaut3Viviana Jehová González4Ester Vázquez5Maurizio Prato6Mauro Tretiach7Dipartimento di Bioscienze, Università di Milano, via G. Celoria 26, Milano 20133, ItalyDipartimento di Scienze della Vita, Università di Trieste, via L. Giorgieri 10, Trieste 34127, Italy; Corresponding author.Centre Interuniversitaire de Recherche et d′Ingénierie des Matériaux - CIRIMAT, Université Paul-Sabatier, 118 Route de Narbonne, Cedex 9, Toulouse 31062, FranceCentre Interuniversitaire de Recherche et d′Ingénierie des Matériaux - CIRIMAT, Université Paul-Sabatier, 118 Route de Narbonne, Cedex 9, Toulouse 31062, FranceInstituto Regional de Investigación Científica Aplicada (IRICA), Universidad de Castilla-La Mancha, Avda. Camilo José Cela, Ciudad Real 13071, SpainInstituto Regional de Investigación Científica Aplicada (IRICA), Universidad de Castilla-La Mancha, Avda. Camilo José Cela, Ciudad Real 13071, Spain; Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1B, Ciudad Real 13071, SpainDipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, via L. Giorgieri 1, Trieste 34127, ItalyDipartimento di Scienze della Vita, Università di Trieste, via L. Giorgieri 10, Trieste 34127, ItalyGraphene-related materials (GRMs) are used in many innovative applications for their outstanding physico-chemical properties. Their possible release could have critical consequences for the environment. According to a European Union regulation, one of the test guidelines (TG) that must be applied to check the environmental hazard of new substances is the OECD TG 201 - Algae and Cyanobacteria Growth Inhibition Test. It was developed for water-soluble substances, whereas GRMs are not: dispersed in aqueous media, they tend to aggregate and settle, changing their bioavailability. This work aims to evaluate the applicability of the TG 201 to GRMs by investigating the stability of GRMs dispersions (GDS) in the TG 201 medium, focusing on the stability criterion of TG 201, i.e. maintaining ± 20 % of the nominal initial concentration. Based on flow-cytometry, Turbiscan and Utermöhl sedimentation chamber measurements, the following factors were tested: (i) particle composition and (ii) concentration; (iii) application of turbulence; (iv) addition of dispersants; (v) presence/absence of the target organism. Strong agglomeration/aggregation and sedimentation phenomena were observed for all materials under all tested conditions, thus the stability criterion of TG 201 was not met. Nevertheless, this can be satisfied by allowing an adequate period of time (approx. 6 h) for the GRM dispersion to stabilize after its preparation. Only then, a detailed physico-chemical characterization of the suspended material is required, which must be reiterated at the end of the test.http://www.sciencedirect.com/science/article/pii/S0147651325002246TG 201AlgaeApplicabilityGraphene-related materialsOECD test guidelinesSedimentation
spellingShingle Giada Caorsi
Fabio Candotto Carniel
Morgan Légnani
Emmanuel Flahaut
Viviana Jehová González
Ester Vázquez
Maurizio Prato
Mauro Tretiach
Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability matters
Ecotoxicology and Environmental Safety
TG 201
Algae
Applicability
Graphene-related materials
OECD test guidelines
Sedimentation
title Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability matters
title_full Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability matters
title_fullStr Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability matters
title_full_unstemmed Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability matters
title_short Applicability of the OECD Test Guideline 201 to graphene-related materials: Dispersion stability matters
title_sort applicability of the oecd test guideline 201 to graphene related materials dispersion stability matters
topic TG 201
Algae
Applicability
Graphene-related materials
OECD test guidelines
Sedimentation
url http://www.sciencedirect.com/science/article/pii/S0147651325002246
work_keys_str_mv AT giadacaorsi applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters
AT fabiocandottocarniel applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters
AT morganlegnani applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters
AT emmanuelflahaut applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters
AT vivianajehovagonzalez applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters
AT estervazquez applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters
AT maurizioprato applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters
AT maurotretiach applicabilityoftheoecdtestguideline201tographenerelatedmaterialsdispersionstabilitymatters