National foreword

This British Standard is the UK implementation of EN ISO 19337:2024. It is identical to ISO 19337:2023. It supsersedes BS ISO 19337:2023, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee NTI/1, Nanotechnologies.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2023.

This European Standard was approved by CEN on 9 September 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.

European foreword

The text of ISO 19337:2023 has been prepared by Technical Committee ISO/TC 229 "Nanotechnologies” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 19337:2024 by Technical Committee CEN/TC 352 “Nanotechnologies” the secretariat of which is held by AFNOR.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2025, and conflicting national standards shall be withdrawn at the latest by March 2025.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

Any feedback and questions on this document should be directed to the users’ national standards body. A complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United Kingdom.

Endorsement notice

The text of ISO 19337:2023 has been approved by CEN as EN ISO 19337:2024 without any modification.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies.

This second edition cancels and replaces the first edition (ISO/TS 19337:2016) which has been technically revised.

The main changes are as follows:

“the flow of measurements” has been improved as shown in Figure A.1;
the status of Annex A has been changed from informative to normative;
“5.2 Endotoxin” has been replaced by “5.5 Contamination”.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

Before nano-objects enter onto the market, their possible impact on human health and the environment should be carefully evaluated.

In vitro toxicity assays using cultured cells are frequently used as a tool in screening materials for possible hazardous properties. The testing provides essential information for understanding the mechanisms of biological effects induced by the materials. However, nano-objects require specific considerations with respect to the in vitro toxicity assays, because of their unique behaviour in cell culture medium. For example, immediately after the introduction of nano-object samples into the culture medium, the nano-objects can undergo changes in

ionic dissolution,
corona formation, or
aggregation/agglomeration

leading to alteration in particles size and sedimentation. Therefore, it is critical to consider the above-mentioned phenomena in clarifying if the observed effects are related to the tested nano-object itself or from uncontrolled sources and to avoid false interpretation of assay results. For example, the corona formation, metal ion release from the nano-objects and impurities (residual from the nano-object synthesis process) can interfere with some in vitro assays^[¹^], producing inaccurate results. Additionally, the formation of agglomerates and aggregates can alter the toxicity of a suspension. It is important to carefully assess and describe the characteristics of the suspension of nano-objects being tested.

Therefore, the rigorous characterization of the working suspension prior and during in vitro toxicity assays on these characteristics is essential to exclude the in vitro experimental artefacts. In this document, the essential characteristics related to these three phenomena and applicable measurement methods were summarized. On the other hands, this document does not include a strategy to select the appropriate techniques from the applicable measurement methods because the working suspensions that contain nano-object samples for in vitro toxicity assays has the different materials components, concentration and sizes; thus, the appropriate selection is depending on the investigators. While the related informative annexes and the list of references in the Bibliography are included in this document to assist with appropriate method selection by investigators to make allowance for the characterization method selection, optional methods are also given in this document. In Clause 6, the details of the characterization methods/procedures are described; therefore, the appropriateness of the characterization can be judged.

The intention of this document is for reliable test results on nano-object toxicity to be shared and communicated among stakeholders of nano-objects, such as regulators, general public, manufacturers and end users.

1 Scope

This document describes the characteristics of working suspensions of nano-objects to be considered when conducting in vitro assays to evaluate inherent nano-object toxicity. In addition, the document identifies applicable measurement methods for these characteristics.

This document is applicable to nano-objects, and their aggregates and agglomerates greater than 100 nm.

This document intends to help clarify whether observed toxic effects come from tested nano-objects themselves or from uncontrolled sources.

2 Normative references

3 Terms and definitions

4 Abbreviated terms

5 Characteristics and measurement methods

5.1 General

5.2 Stability of working suspensions

5.3 Concentration of metal ions

5.4 Concentration of culture medium components

5.5 Contamination

6 Reporting

6.1 General

6.2 Name of nano-objects and manufacturing information

6.3 Composition and metallic elements included in the nano-object sample

6.4 Culture medium and serum

6.5 Measurement results

6.6 Optional methods

Bibliography

BS EN ISO 19337:2024

Nanotechnologies. Characteristics of working suspensions of nano-objects for in vitro assays to evaluate inherent nano-object toxicity

Current

Published:

31 Oct 2024