SSbD Knowledge Sharing Portal

Test methods

Introduction

Safety and sustainability assessment and thus also SSbD assessments rely on data generated by applying test methods targeting endpoints of interest. For SSbD assessment in early stages of innovation, especially data originating from alternative and new approaches (so-called new approach methodologies, NAMs) will become important. Such approaches allow high throughput screening for potential adverse effects of chemicals or materials and provide opportunities to gain first indications of red-flags and hotspots in a faster and less resource demanding manner. Still, the data obtained might come with a higher degree of uncertainty than data collected using standardised and harmonised test methods. Standardised and harmonised test methods are laid down in test guidelines, guidance documents or technical guidance approved by OECD or standardisation bodies. These methods are internationally validated and by this they ensure significance and quality of data. However, generation of data by these methods is often time and resource intensive. Thus, standardised and harmonised test methods become relevant for SSbD applied at later stages of innovation, preparing for compliance with regulatory reporting and assessment requirements. In the European Union, the Test Methods Regulation ↗ lists such test methods that are officially recognised as suitable for assessing the physicochemical, toxicological, and ecotoxicological properties of chemicals under the REACH Regulation ↗. However, test methods listed there are also used for the assessment of chemicals in other chemicals and product specific legislation.

New Approach Methodologies

In an era of rapid innovation, NAMs are emerging as cost-effective and time-efficient alternatives to assess the safety of chemicals, materials and products. Traditional OECD Test Guidelines (TGs) may be also too costly and time-consuming for SSbD assessments in early innovation. The European Commission, EU Member States, and the OECD have made strong efforts to push forward the development of NAMs ↗ for regulatory acceptance and use with the additional aim to replace, reduce and refine laboratory animal tests.

NAMs include:

In vitro assays (experiments using cells and tissues instead of whole organisms),
In silico models (computer-based simulations),
Biotechnological and computational approaches (e.g. omics-based tests, AI-driven assessments),
(Quantitative) Structure-Activity Relationships ([Q]SARs), which predict toxicity based on chemical structure.

NAMs can also include in vivo methods to improve the understanding of toxic effects of chemicals. NAMs are often included in Integrated Approaches to Testing and Assessment (IATA). To aid such IATAs, Adverse Outcome Pathways ↗ (AOPs) can provide a framework for organising the data collected and support the understanding of toxic effects at a mechanistic level. AOPs include information from different levels of biology (e.g. molecule, cell, organ, organ system, organism) to evaluate relationships between key events and adverse effects. The OECD has endorsed a set of AOPs ↗.

These new methodologies can provide opportunities to assess the safety of chemicals, materials, and products earlier in the innovation process, allowing for high throughput screening of potential negative impacts.

Thereby, SSbD provides an arena to apply, test and improve new test approaches without regulatory constraints. In consequence, application of these methods in SSbD assessments will increase their maturity and improve data quality received which will increase their potential for later use in addressing legal obligations, e.g. by evolving into a harmonised test method.

Standardised Test Methods: a common language for industry

Standardised test methods are developed and validated by standardisation bodies such as the International Organisation for Standardization ↗ (ISO), the European Committee for Standardisation ↗ (CEN) or national standardisation bodies. These methodologies respond to market needs and are primarily driven by industry to facilitate international collaboration. By following standardised protocols, companies can communicate efficiently and confidently about product safety, ensuring that all partners in supply chain are on the same page. These test protocols can be accessed through standardisation bodies for a fee, providing a widely accepted framework for testing.

Harmonised OECD Test Methods: ensuring global safety compliance

Harmonised test methods are developed and validated under the umbrella of the Organisation for Economic Co-operation and Development ↗. These methods – known as OECD Test Guidelines (TGs) – are agreed upon by member countries. They provide a harmonised approach to fulfilling chemical safety requirements of various national and international regulations. With that, they respond to the need for accepted methods to fulfil information requirements of respective chemical legislation.

A key advantage of the OECD TGs is the principle of Mutual Acceptance of Data ↗ (MAD). This means that if a test is conducted according to OECD TGs and the Principles of Good Laboratory Practice ↗ (GLP) in one OECD country, the results must be accepted in other OECD countries. Test study data must be accepted, but the particular use and interpretation of the data may differ between countries. This not only saves time and resources, but also reduces the need for duplicate testing, thereby lowering costs and trade barriers.

OECD TGs – together with accompanying Guidance Documents (GDs) – are publicly accessible via the OECD website ↗.
OECD TGs and GDs can also be key for the SSbD assessment as they ensure consistency, reliability and comparability of hazard data. Compared to other methods, their utilisation will minimise the uncertainty in the SSbD assessment and facilitate regulatory acceptance of a chemical and its application at market entry stage. However, their application usually affords high laboratory efforts, sometimes animal testing and is often cost intensive. Thus, depending on the effort, their utilisation in SSbD might be limited to later innovation stages.

Learn more about OECD Test Guidelines

Understanding and navigating the complex process of OECD TG development can be challenging. To bridge this gap, the EU H2020 Project NanoHarmony has developed the NanoHarmony OECD TG/GD Process Mentor ↗ – an interactive, web-based tool designed to guide stakeholders through the development process of OECD TGs and GDs.

As an online guidance tool, the NanoHarmony Process Mentor is intended for anyone with an interest in the OECD TG development process, including those interested in leading or participating in TG development.

For example, the Process Mentor can be used by researchers who want to understand how the methods they developed can be taken into the OECD process for regulatory acceptance. It can also be used for educational purposes, e.g. by university teachers who educate their students on how science is used in regulation, or by governments to train the next generation of regulatory scientists. For this specific purpose, the Process Mentor hosts the NanoHarmony training material ↗. The NanoHarmony training material provides a low-level entry into the topic of harmonised OECD TGs and how science can contribute to them. The Process Mentor provides more in-depth information.