European Observatory for Nanomaterials

PHYSICO-CHEMICAL PROPERTIES

Number based particle size distribution with indication of the number fraction of the constituent particles in the size range 1-100 nm

VI

Characterisation parameter for nanoforms and sets of nanoforms.

Appendix R7-1 for nanoforms applicable to Chapter R7a also partially covers the information requirements.

Covered by the guidance for registration of nanoforms/sets of nanoforms. Partially covered too by Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance under Granulometry section.

Advice in the guidance on nanoforms and sets of nanoforms that is aligned with the OECD TG 125 on Nanomaterial Particle Size and Size Distribution of Nanomaterials.

Description of surface functionalisation or treatment and identification of each agent including IUPAC name and CAS or EC number

VI

Characterisation parameter for nanoforms and sets of nanoforms.

Appendix R7-1 for nanoforms applicable to Chapter R7a also partially covers the information requirements.

Covered by the guidance for registration of nanoforms/sets of nanoforms.

Advice in the guidance on nanoforms and sets of nanoforms.

For the time being, it is possible to use protocols from research projects and/or general techniques which is taken into account in current ECHA guidance.

OECD WNT project 1.6: Guidance document on identification and quantification of the surface chemistry and coatings on nano- and microscale materials under development from 2019.

Shape, aspect ratio and other morphological characterisation: crystallinity, information on assembly structure

VI

Characterisation parameter for nanoforms and sets of nanoforms.

Appendix R7-1 for nanoforms applicable to Chapter R7a also partially covers the information requirements.

Covered by the guidance for registration of nanoforms/sets of nanoforms.

Advice in the guidance on nanoforms and sets of nanoforms that is aligned with the OECD TG 125 on Nanomaterial Particle Size and Size Distribution of Nanomaterials.

Currently, there are protocols from research projects and/or standard methods and/or scientific literature available for determination of crystallinity/assembly structure.

Specific surface area (volume or mass)

VI

Characterisation parameter for nanoforms and sets of nanoforms.

Appendix R7-1 for nanoforms applicable to Chapter R7a also partially covers the information requirements.

Covered by the guidance for registration of nanoforms/sets of nanoforms.

ISO/TR 14187 provides an introduction to (and some examples of) the types of information that can be obtained about nanostructured materials using surface-analysis tools. Of equal importance, both general issues or challenges associated with characterising nanostructured materials and the specific opportunities or challenges associated with individual methods are identified.

A new OECD test guideline OECD TG 124 on Determination of the Volume Specific Surface Area of Manufactured Nanomaterials was released in June 2022.

7.7 Solubility

VII

Dissolution rate to be determined also.

Assessment of dispersion as confounding effect.
 

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

Guidance document 318 for the testing of dissolution and dispersion stability of nanomaterials, and the use of the data for further environmental testing and assessment | Excel

OECD WNT Project 1.5: Guidance document on determination of solubility and dissolution rate of nanomaterials in water and relevant synthetic biological media ongoing for new guidance document/test guideline.

OECD WNT Project 3.10: New test guideline on dissolution rate of nanomaterials in aquatic environment ongoing.

7.8 Partition coefficient octanol/water

VII

Dispersion stability to be considered when Kow is not applicable.

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance  instead of partially covers the information requirements.

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

OECD test guideline 318 is available for dispersion stability but is not offering advice on differentiation between dissolution and dispersion. Further data or advice provided in the Guidance document 318 for the testing of dissolution and dispersion stability of nanomaterials, and the use of the data for further environmental testing and assessment.

7.14 bis Dustiness

VII

New information requirements for nanoforms

CEN standards are available as of autumn 2018.

OECD WNT Project 1.8: Test guideline on determination of the dustiness of manufactured nanomaterials - new guidance document/test guideline on dustiness under development.

7.19 Further information on physchem properties

IX

Information that influences hazard or exposure for the nanoforms.

Partly covered by the read-across guidance for nanoforms of the same substances.

OECD decision tree for physical chemical characterisation is avaiable.

OECD framework on physical chemical characterisation was released in May 2019 and can be used indicatively for assessing relevance and applicability of existing methods/standards.

OECD WNT Project 1.7: New test guideline on determination of surface hydrophobicity of manufactured nanomaterials under development, which can be used to provide further information on physical chemical properties.

ISO/TR 11360:2010 describes a classifying system, termed a “nano-tree”, upon whose basis wide ranges of nanomaterials can be categorized, including nano-objects, nanostructures and nanocomposites of various dimensionality of different physical, chemical, magnetic and biological properties.

HUMAN HEALTH

8.4.1. In vitro gene mutation study in bacteria

VII

Consider mammalian cell study instead
(if not appropriate)

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

Relevant OECD test guidelines to be reviewed. Alternative methods available such as the use of mammal cell lines.

8.5.1 Acute toxicity by oral route

VII

Use the most appropriate route of exposure (e.g. 8.5.2 or 8.5.3).

Limited advice in Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

Not applicable

8.5 Acute toxicity

VIII

Second route
(choose most appropriate)

Limited advice in Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

OECD guidance 39

8.6.1 Short-term repeat dose toxicity

VIII

Toxicokinetics including lung clearance.

Further studies may be needed (indirect genotox).

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

Currently no specific concern about the use of existing method. Sample preparation guidance offers support.

8.6.2 Sub-chronic

IX

Toxicokinetics including lung clearance.

Further studies may be needed (indirect genotox).

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

Currently no specific concern about the use of existing method. Sample preparation guidance offers support.

8.6.3

X

(long term repeated toxicity study proposed > 12 months)
For nanoforms: physchem properties to be taken into account when assessing the need of a long-term study.

The need to consider physchem properties of nanoforms when conducting tests is acknowledged for all annexes.

8.8 Toxicokinetics

8.8.1 Assessment of the toxicokinetic behaviour of the substance to the extent that can be derived from the relevant available information

VIII

Perform if 8.8.1 not available

The aspect of toxicokinetics for nanoforms is provided.
Appendix R7-2 for nanomaterials applicable to Chapter R7c Endpoint specific guidance.

ISO/TR 22019:2019 Nanotechnologies — Considerations for performing toxicokinetic studies with nanomaterials. This document describes the background and principles for toxicokinetic studies relevant for nanomaterials. Annex A shows the definitions for terminology with respect to toxicokinetics as used in OECD TG 417:2010.

Development of new test guideline on toxicokinetics to accommodate testing of (nano)particles has been initiated by the Netherlands. The Dutch initiative is part of the Malta Initiative and is now a project proposal at the OECD’s Working Party on Manufactured Nanomaterials (WPMN).

ENVIRONMENT

9.1.1. Short term toxicity in invertebrates

VII

Waiver based on solubility (only) not acceptable for nanomaterials.

Consider nanomaterials also dispersion stability.

High dissolution rate or low dispersion stability can be used to justify that short-term testing is sufficient.

Partially covered in guidance released in 2017:
Appendix R7-1 for nanomaterials applicable to Chapter R7b (Endpoint specific guidance).

Guidance document 317 on aquatic and sediment toxicological testing of nanomaterials.

ISO/TS 20787:2017 specifies a test method, aiming to maximize repeatability and reliability of testing, to determine whether manufactured nanomaterials are toxic to aquatic organisms, specifically Artemia sp. nauplius.

ISO/TS 20787:2017 is intended to be used by ecotoxicological laboratories that are capable in the hatching and culturing of Artemia sp. and the evaluation of toxicity of nanomaterials using Artemia sp. nauplius.

This method uses Artemia sp. nauplii in a simulated environment, artificial seawater, to assess effects of nanomaterials.

ISO/TS 20787:2017 is applicable to manufactured nanomaterials that consist of nano-objects such as nanoparticles, nanopowders, nanofibres, nanotubes, nanowires, as well as aggregates and agglomerates of such manufactured nanomaterials.

9.1.2. Grow inhibition study on aquatic plants

VII

Waiver based on solubility (only) not acceptable for nanomaterials.

Consider nanomaterials also dispersion stability.

Partially covered in guidance released in 2017:
Appendix R7-1 for nanomaterials applicable to Chapter R7b (Endpoint specific guidance).

Guidance document 317 on aquatic and sediment toxicological testing of nanomaterials

ISO/TS 20787:2017 specifies a test method, aiming to maximize repeatability and reliability of testing, to determine whether manufactured nanomaterials are toxic to aquatic organisms, specifically Artemia sp. nauplius.

ISO/TS 20787:2017 is intended to be used by ecotoxicological laboratories that are capable in the hatching and culturing of Artemia sp. and the evaluation of toxicity of nanomaterials using Artemia sp. nauplius.

This method uses Artemia sp. nauplii in a simulated environment, artificial seawater, to assess effects of nanomaterials.

ISO/TS 20787:2017 is applicable to manufactured nanomaterials that consist of nano-objects such as nanoparticles, nanopowders, nanofibres, nanotubes, nanowires, as well as aggregates and agglomerates of such manufactured nanomaterials.

9.1.3 Short-term toxicity testing on fish

VIII

Waiver-based on solubility (only) not acceptable for nanomaterials.

Consider nanomaterials also dispersion stability.

High dissolution rate or low dispersion stability can be used to justify that short-term testing is sufficient.

Partially covered in guidance released in 2017:
Appendix R7-1 for nanomaterials applicable to Chapter R7b (Endpoint specific guidance).

Guidance document 317 on aquatic and sediment toxicological testing of nanomaterials

ISO/TS 20787:2017 specifies a test method, aiming to maximize repeatability and reliability of testing, to determine whether manufactured nanomaterials are toxic to aquatic organisms, specifically Artemia sp. nauplius.

ISO/TS 20787:2017 is intended to be used by ecotoxicological laboratories that are capable in the hatching and culturing of Artemia sp. and the evaluation of toxicity of nanomaterials using Artemia sp. nauplius.

This method uses Artemia sp. nauplii in a simulated environment, artificial seawater, to assess effects of nanomaterials.

ISO/TS 20787:2017 is applicable to manufactured nanomaterials that consist of nano-objects such as nanoparticles, nanopowders, nanofibres, nanotubes, nanowires, as well as aggregates and agglomerates of such manufactured nanomaterials.

9.1.4 Activated sludge respiration inhibition testing

VIII

Waiver-based on solubility (only) not acceptable for nanomaterials.

Consider nanomaterials also dispersion stability.

Partially covered in guidance released in 2017:
Appendix R7-1 for nanomaterials applicable to Chapter R7b (Endpoint specific guidance).

Guidance document 317 on aquatic and sediment toxicological testing of nanomaterials

ISO/TS 20787:2017 specifies a test method, aiming to maximize repeatability and reliability of testing, to determine whether manufactured nanomaterials are toxic to aquatic organisms, specifically Artemia sp. nauplius.

ISO/TS 20787:2017 is intended to be used by ecotoxicological laboratories that are capable in the hatching and culturing of Artemia sp. and the evaluation of toxicity of nanomaterials using Artemia sp. nauplius.

This method uses Artemia sp. nauplii in a simulated environment, artificial seawater, to assess effects of nanomaterials.

ISO/TS 20787:2017 is applicable to manufactured nanomaterials that consist of nano-objects such as nanoparticles, nanopowders, nanofibres, nanotubes, nanowires, as well as aggregates and agglomerates of such manufactured nanomaterials.

9.2 Degradation

VIII

For nano consider morphological, chemical and other transformations on shape size, etc.

Partially covered in guidance released in 2017:
Appendix R7-1 for nanomaterials applicable to Chapter R7b (Endpoint specific guidance).

OECD WNT 3.16 project: Guidance document environmental abiotic transformation of nanomaterials under development. This guidance aims to cover abiotic core transformation and coating degradation. Both documents likely to be available in 2023 or 2024. It may be possible to conduct a qualitative assessment in the meantime.

9.2.2.1 Hydrolysis as function of pH

VIII

Waiver-based on solubility (only) not acceptable for nanomaterials.

Consider nanomaterial dissolution rate and dispersion stability

9.3.1 Adsorption desorption screening

VIII

Justification required to use Kow, dissolution rate or dispersion stability for waving the study.

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

OECD Guidance Document No. 342 on testing Nanomaterials using OECD TG No. 312 “Leaching in soil columns" is available since July 2021 and helps adapting the test to provide with attachment efficiency measurements for nanomaterials.

9.2.1.2 Simulation testing on ultimate degradation in surface water

IX

Waiver-based on solubility (only) not acceptable for nanomaterials.

Consider nanomaterials also dispersion stability.

9.3.2 Bioaccumulation in aquatic species, preferably fish

IX

Justification required to use Kow, dissolution rate etc.

Partially  covered in guidance released in 2021:
Appendix R7-2 for nanomaterials applicable to Chapter R7c Endpoint specific guidance.

OECD WNT Project 3.12: New guidance document on assessing the apparent accumulation potential for nanomaterials for OECD test guideline 305 (dietary exposure) expected to be finalised by 2024.

A decision tree (OECD guidance document) for tiered testing of bioaccumulation) is under development.

9.3.3 Further information on adsorption desorption depending on the results of the study required in Annex VIII

IX

Justification required to use Kow, dissolution rate or dispersion stability for waiving the study.

Appendix to Guidance R7a contains up to date information and advice on how to perform the tests. (Appendix R7-1 for nanoforms applicable to Chapter R7a Endpoint specific guidance).

OECD Guidance Document No. 342 on testing Nanomaterials using OECD TG No. 312 “Leaching in soil columns" is available since July 2021 and helps adapting the test to provide with attachment efficiency measurements for nanomaterials.

Furthermore a report to be added to OECD GD 318 will be made available for manufactured nanomaterial removal in wastewater treatment plants: activated sludge sorption isotherm, could be used as complementary information on sorption in wastewater sludge.

9.4 Effects in terrestrial organisms

IX

Short-term may be sufficient if nanomaterial not persistent and has low potential of absorption to soil.

Partially  covered in guidance released in 2021:
Appendix R7-2 for nanomaterials applicable to Chapter R7c Endpoint specific guidance.

Potential development or enlargement of the OECD guidance document on aquatic and sediment testing to soil. Still up for discussion and could be addressed in a separate guidance document.