The EU’s Push to Phase Out Animal Testing of Chemicals

A long-awaited roadmap reflects a gradual shift toward alternative methods, and a realization that an ambitious transition like this will take a long time 

This month, the European Union released a 26-page roadmap that detailed its vision for transitioning away from traditional animal testing methods—long the standard for vetting chemicals—to innovative non-animal approaches. At the same time, the EU said it remains committed to preserving the integrity of safety evaluations, which ensure a high level of protection for human and animal health and the environment.

There are already solid examples of New Approach Methodologies that have replaced animal testing in chemical testing. But their number pales in comparison to the number of tests still needed in both small- and large-animal models. So, what are the biggest challenges facing the industry and regulators as they adjust to the goals laid out in this ambitious plan? Read on for some perspective on some of the biggest questions facing the field of chemical testing. 

Why are chemical safety assessments needed, and how are they typically done? 

Chemical safety assessments are essential to ensure that substances placed on the EU market do not pose unacceptable risks to human health or the environment. This requirement lies at the core of all European chemical legislation, such as EU REACH.

Traditionally, safety assessments have relied on laboratory studies, including animal tests, to evaluate endpoints such as skin and eye irritation, sensitization, repeated-dose toxicity, reproductive toxicity, and environmental effects. However, over the past two decades, non-animal methods have become increasingly important. These include in vitro assays, QSAR modeling, read-across approaches, and integrated testing strategies. Today, chemical safety assessments often combine multiple sources of evidence to generate robust, scientifically sound conclusions.

What exactly does the EU Roadmap, released this month, change for laboratories conducting chemical tests? 

The roadmap establishes a long-term framework, supported by 22 actions, for accelerating the development, validation, acceptance, and implementation of non-animal methods across European chemical legislation.

For laboratories, the importance lies in the future direction of testing. The Roadmap signals a gradual shift toward approaches that reduce the reliance on animal studies while maintaining a high level of protection for human health and the environment. Laboratories will be called to play a central role in generating the scientific evidence needed to support this transition by responding to the growing opportunities to develop expertise in New Approach Methodologies (NAMs). The Roadmap also promotes collaboration between regulators, industry, and laboratories to help ensure that scientific innovation can be translated into regulatory practice more efficiently.

The EU Roadmap states that non-animal approaches must deliver a level of protection equivalent to that of currently established methods. What are examples of alternative approaches that do that, and when are animal models still the best fit?

Significant progress has already been made in replacing animal testing for several toxicological endpoints. Validated in vitro methods are routinely used to assess skin and eye irritation, skin sensitization, and genotoxicity, while in silico tools, read-across approaches, and integrated testing strategies can also provide valuable information by using existing data to predict hazards. These methods provide regulatory- and human-relevant reproducible, and high-throughput data.

However, challenges remain for complex endpoints such as repeat-dose toxicity, reproductive and developmental toxicity. Certain systemic effects involve interactions between multiple organs and biological processes that are not yet fully captured in non-animal approaches. The roadmap recognizes this challenge and aims to accelerate the development of next-generation methods to address these remaining gaps.

Validation is key for any testing method. How challenging will it be for laboratories to validate new methods and achieve regulatory acceptance?

Validation remains one of the greatest challenges in the transition towards animal-free safety assessment. New methods must demonstrate reliability, reproducibility, and regulatory relevance before they can be broadly accepted. This process often requires multi-laboratory studies, independent review and alignment across different regulatory sectors.

The Roadmap recognizes the challenge and proposes actions to accelerate validation, improve coordination and create opportunities for regulators and stakeholders involved. One example is the use of ‘safe spaces’ where innovative methods can be explored and discussed without immediately affecting regulatory obligations. For testing laboratories, the challenge is not only developing innovative methods but also generating the evidence needed to prove their performance. In addition, upscaling of validated non-animal methods for routine application remains a significant hurdle.

What are the biggest challenges facing companies in adapting to the directives in the EU Roadmap?

The greatest challenge is managing the transition while continuing to meet current regulatory requirements. Early and structured dialogue with regulators will be critical to building confidence in NAMs and defining acceptable use cases. In parallel, the increasing role of AI and digital tools introduces both opportunities and uncertainties, particularly regarding transparency, data quality, and regulatory trust.

As the Roadmap acknowledges, progress differs across toxicological endpoints, requiring companies to navigate in a mixed landscape of established and emerging approaches. It also highlights the need for greater data sharing, cross-sector collaboration, training, and international harmonization. Companies must stay aligned with evolving scientific and regulatory expectations, understand which approaches are accepted for specific applications, adapt testing strategies, invest in new expertise and learn how to integrate multiple sources of evidence into regulatory submissions.

Elisavet Kyriakou, PhD, joined Charles River Laboratories in 2017 as regulatory toxicologist, where she became responsible for registration of new and existing industrial chemicals under REACH. She performs toxicological evaluations and has written toxicological advice reports for industrial chemicals, agrochemicals and pharmaceuticals. Elisavet has experience in interpreting and summarizing toxicological results and in project management. In addition, she has experience with IUCLID6, read-across, (Q)SARs, derivation of, for example, Permitted Daily Exposure values (PDEs), Derived No Effect Levels (DNELS), and other toxicologically relevant values and substance classification and labeling. She is also actively involved as an advisory member in the local Animal Welfare Body and in Charles River’s global Scientific Integrity Committee. Elisavet has a PhD degree in behavioral neuroscience.