Regulatory utility of non-animal test methods for chemical safety assessments in the EU
More than 100,000 people have signed an open letter to the European Commission and the European Chemicals Agency (ECHA) demanding an end to animal testing1. The Registration, Evaluation, Authorization & Restriction of Chemicals (REACH) regulation mandates that specific information requirements must be fulfilled in order to place new chemicals on the market in Europe.
If there are gaps in the existing information for a chemical, testing must be performed. Many of the higher tier hazard endpoints, such as mutagenicity and repeated dose toxicity, require testing to be performed on vertebrate animals. Due to the strict information requirements under REACH, the EU has established itself in the forefront of testing for the assessment of chemical hazards.
In November 2017, ECHA published a report on the regulatory applicability of non-animal approaches under REACH, the Classification, Labeling & Packaging regulations (CLP) and Biocidal Products Regulation (BPR)2. The report includes a detailed summary of the presently available alternatives to animal testing as well as methods that are currently under development. Some important aspects that should be considered in the application of non-animal test methods are described in the report, including the combination of data for regulatory adaptations. ECHA claims that while significant progress has been made toward alternatives to animal testing on lower-tier endpoints such as skin sensitization, the full replacement of vertebrate testing with non-animal approaches is not yet foreseeable.
ECHA asserts that they are committed to promoting the development and use of non-animal approaches. However, they also maintain that the primary objective of REACH is to assure a high level of protection to human health and the environment and that this objective must not be compromised.
For those substances that are produced or imported into Europe in quantities of less than 100 tonnes per year, the toxicological information required under REACH is less complex and there are appropriate in-vitro methods and existing experimental data available. The primary focus then, are the methods in place for testing substances produced or imported in quantities greater than 100 tonnes per year, which require more complex data endpoints. New methodologies that have the potential to provide cruelty-free human relevant data, such as high throughput assessment methods that can support alternative approaches, are under development.
Current landscape and test methods used under REACH
EU chemical legislation authorizes animal testing only as a last resort; existing data and alternative methods should be used to fulfill requirements when available. Registrants may only carry out new vertebrate tests when all other relevant data sources have been exhausted. The use of non-animal approaches is promoted according to the 3Rs principle of animal use: “Replacement, Reduction and Refinement.” Animal tests may be replaced with tests that use non-animal systems, invertebrate or early-stage vertebrate species or other non-animal approaches. Effort should be made to reduce the number of animals required to achieve an objective by maximizing the information obtained per animal, reducing the number of animals used in each test and limiting subsequent testing. Also, test methods may be refined to enhance animal wellbeing and cause minimal pain or distress.
Data sharing is one way that REACH minimizes the number of animal tests performed. Companies that register hazardous chemicals are obliged to jointly submit information about their hazardous properties to ECHA. In this way, test results for the same substance can be shared to prevent the repetition of animal studies. Additionally, there are alternative methods and approaches that may be applied; existing data from animal studies can be used to fulfill requirements and the properties of untested substances may be predicted by comparing them to chemically similar substances in a technique called read-across.
Under the REACH regulation, requirements for in-vivo studies (performed in a living organism) have now been replaced by in-vitro methods (performed in a controlled environment outside a living organism, such as in a test tube) for endpoints including serious eye damage/eye irritation, skin corrosion/irritation and skin sensitization. Unfortunately, the availability of in- vitro methods for higher-tier endpoints such as carcinogenicity is still limited. The information requirements for higher-tier endpoints are more complex, making the development of direct replacements a challenge. A more practical solution may be the combination and integration of various humane test methods into assessment strategies for the evaluation of complex endpoints.
Over the past decade there has been progress with concepts such as the Integrated Approach to Testing and Assessment (IATA) and Adverse Outcome Pathway (AOP) frameworks. Both IATA and AOP allow for the integration of data points from various non-animal approaches into useful information on the (eco)toxicological properties of a substance. The weight-of-evidence (WoE) approach is used to consider all relevant information available for a hazard assessment. By reviewing all available data, a conclusion may be drawn without performing further studies. All of these techniques reduce the need for animal testing under EU chemical legislation by making practical use of information that is readily available or which may be obtained using non-animal approaches.
On the horizon there are innovative non-animal approaches that provide a comprehensive understanding of complex toxicity mechanisms. In-vitro microsystems and high-throughput/high-content methods that are currently under development will require further standardization, particularly with respect to interpretation of the results and validation, before they are fit for regulatory use.
To achieve the more widespread application of cruelty-free approaches, focus should be aimed toward ways to interpret and make practical use of available data and test methods. The current methods for fulfilling higher tier information requirements are strongly dependent on the direct effects on humans or animals. It will be necessary to integrate available resources to establish less detrimental means to advance our understanding of how chemicals interact with humans and the environment.
Resources & guidance on non-animal test methods
Raising awareness around the issues of vertebrate animal testing in the regulatory compliance field is a step towards positive change. If your business is required to perform chemical safety testing under REACH or other regulatory safety legislation, it is important to educate yourself so that you can fulfill the requirements in an informed and responsible manner. There are a variety of helpful resources available to help you get started.
The database service on non-animal approaches (DB-ALM) operated by the European Commission’s Joint Research Centre (JRC) is a public database that provides evaluated information on non-animal approaches in biomedical sciences and toxicology for research and regulatory purposes3.
The ECHA guidance documents are a great source of information to aid in fulfilling the requirements of the REACH regulation and BPR4. New and improved test methods are also frequently updated on the ECHA website5.
While these resources are directed towards EU companies, they contain a great deal of information for anyone interested in learning more about non-animal methods and alternatives to animal testing. SPRAY