The EU Directive 2010/63/EU on the protection of animals used for scientific purposes and other EU regulations, such as REACH and the Cosmetic Products Regulation advocate for a change in the way ...toxicity testing is conducted. Whilst the Cosmetic Products Regulation bans animal testing altogether, REACH aims for a progressive shift from in vivo testing towards quantitative in vitro and computational approaches. Several endpoints can already be addressed using non-animal approaches including skin corrosion and irritation, serious eye damage and irritation, skin sensitisation, and mutagenicity and genotoxicity. However, for systemic effects such as acute toxicity, repeated dose toxicity and reproductive and developmental toxicity, evaluation of chemicals under REACH still heavily relies on animal tests. Here we summarise current EU regulatory requirements for the human health assessment of chemicals under REACH and the Cosmetic Products Regulation, considering the more critical endpoints and identifying the main challenges in introducing alternative methods into regulatory testing practice. This supports a recent initiative taken by the International Cooperation on Alternative Test Methods (ICATM) to summarise current regulatory requirements specific for the assessment of chemicals and cosmetic products for several human health-related endpoints, with the aim of comparing different jurisdictions and coordinating the promotion and ultimately the implementation of non-animal approaches worldwide. Recent initiatives undertaken at European level to promote the 3Rs and the use of alternative methods in current regulatory practice are also discussed.
This paper reviews regulatory requirements and recent case studies to illustrate how the risk assessment (RA) of chemical mixtures is conducted, considering both the effects on human health and on ...the environment. A broad range of chemicals, regulations and RA methodologies are covered, in order to identify mixtures of concern, gaps in the regulatory framework, data needs, and further work to be carried out. Also the current and potential future use of novel tools (Adverse Outcome Pathways, in silico tools, toxicokinetic modelling, etc.) in the RA of combined effects were reviewed.
The assumptions made in the RA, predictive model specifications and the choice of toxic reference values can greatly influence the assessment outcome, and should therefore be specifically justified. Novel tools could support mixture RA mainly by providing a better understanding of the underlying mechanisms of combined effects. Nevertheless, their use is currently limited because of a lack of guidance, data, and expertise. More guidance is needed to facilitate their application. As far as the authors are aware, no prospective RA concerning chemicals related to various regulatory sectors has been performed to date, even though numerous chemicals are registered under several regulatory frameworks.
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•“Real life” exposure comprises multiple chemicals from different sources and routes.•Chemical legislation rarely considers exposure to multiple chemicals across sectors.•Mixture risk assessment (RA) often faces exposure and hazard data gaps.•Novel alternative tools have high potential for improving mixture RA.•Need for guidance that harmonises approaches across different legislative sectors.
The predominantly animal-centric approach of chemical safety assessment has increasingly come under pressure. Society is questioning overall performance, sustainability, continued relevance for human ...health risk assessment and ethics of this system, demanding a change of paradigm. At the same time, the scientific toolbox used for risk assessment is continuously enriched by the development of “New Approach Methodologies” (NAMs). While this term does not define the age or the state of readiness of the innovation, it covers a wide range of methods, including quantitative structure–activity relationship (QSAR) predictions, high-throughput screening (HTS) bioassays, omics applications, cell cultures, organoids, microphysiological systems (MPS), machine learning models and artificial intelligence (AI). In addition to promising faster and more efficient toxicity testing, NAMs have the potential to fundamentally transform today’s regulatory work by allowing more human-relevant decision-making in terms of both hazard and exposure assessment. Yet, several obstacles hamper a broader application of NAMs in current regulatory risk assessment. Constraints in addressing repeated-dose toxicity, with particular reference to the chronic toxicity, and hesitance from relevant stakeholders, are major challenges for the implementation of NAMs in a broader context. Moreover, issues regarding predictivity, reproducibility and quantification need to be addressed and regulatory and legislative frameworks need to be adapted to NAMs. The conceptual perspective presented here has its focus on hazard assessment and is grounded on the main findings and conclusions from a symposium and workshop held in Berlin in November 2021. It intends to provide further insights into how NAMs can be gradually integrated into chemical risk assessment aimed at protection of human health, until eventually the current paradigm is replaced by an animal-free “Next Generation Risk Assessment” (NGRA).
The June 2019 workshop 21st Century Approaches for Evaluating Exposures, Biological Activity, and Risks of Complex Substances, co-organised by the International Council of Chemical Association's ...Long-Range Research Initiative and the European Commission's Joint Research Centre, is summarised. Focus was the need for improved approaches to evaluate the safety of complex substances. Approximately 10% and 20% of substances registered under the EU chemicals legislation are ‘multi-constituent substances’ and ‘substances of unknown or variable compositions, complex reaction products and biological substances’ (UVCBs), respectively, and UVCBs comprise approximately 25% of the U.S. Toxic Substances Control Act Inventory. Workshop participants were asked to consider how the full promise of new approach methodologies (NAMs) could be brought to bear to evaluate complex substances. Sessions focused on using NAMs for screening, biological profiling, and in complex risk evaluations; improving read-across approaches employing new data streams; and methods to evaluate exposure and dosimetry. The workshop concluded with facilitated discussions to explore actionable steps forward. Given the diversity of complex substances, no single ‘correct’ approach was seen as workable. The path forward should focus on ‘learning by doing’ by developing and openly sharing NAM-based fit-for-purpose case examples for evaluating biological activity, exposures and risks of complex substances.
•This workshop report addresses the hazard and risk assessment of complex substances.•Opportunities are identified to use new approach methodologies for the assessment.•New approach methodologies include in vitro and in silico approaches and read-across.•Exposure modelling enhances the relevance of risk assessment of complex substances.•Insight from current research activities is presented; research needs are identified.
Currently, the assessment of risk to human health from exposure to manufactured chemicals is mainly based on experiments performed on living animals (in vivo). Substantial efforts are being ...undertaken to develop alternative solutions to in vivo toxicity testing. This new paradigm, based on the Mode-of-Action (MoA) framework, postulates that any adverse human health effect caused by exposure to an exogenous substance can be described by a series of causally-linked biochemical or biological key events with measurable parameters. The elaboration of mechanistic knowledge through literature research is necessary for a MoA-driven design of integrated testing strategies using in vitro methods for in vivo predictions. The objective of our ongoing research is to demonstrate the feasibility of an integrated approach to predict human toxicity following the Adverse Outcome Pathway (AOP) framework. In our previous work on MoA with the HepaRG cell model, we developed a strategy to identify chemicals that were hepatotoxic. This pioneered an innovative way of using data from in vitro experiments to group chemicals based on their MoA, which is likely to be an important step in a toxicity testing strategy.
The Technical Committee of Classification and Labelling dealing with harmonized classification of substances and classification criteria under Directive 67/548/EEC on behalf of the European ...Commission nominated an expert group on skin sensitization in order to investigate further the possibility for potency consideration of skin sensitizers for future development of the classification criteria. All substances and preparations should be classified on the basis of their intrinsic properties and should be labelled accordingly with the rules set up in the Directive 67/548/EEC. The classification should be the same under their full life cycle and in the case that there is no harmonized classification the substance or preparation should be self‐classified by the manufacturer in accordance with the same criteria. The Directive does not apply to certain preparations in the finished state, such as medical products, cosmetics, food and feeding stuffs, which are subject to specific community legislation. The main questions that are answered in this report are whether it would be possible to give detailed guidance on how to grade allergen potency based on the existing methods, whether such grading could be translated into practical thresholds and whether these could be set for both induction and elicitation. Examples are given for substances falling into various potency groups for skin sensitization relating to results from the local lymph node assay, the guinea pig maximization test, the Buehler method and human experience.
The body of EU chemicals legislation has evolved since the 1960s, producing the largest knowledge base on chemicals worldwide. Like any evolving system, however, it has become increasingly diverse ...and complex, resulting in inefficiencies and potential inconsistencies. In the light of the EU Chemicals Strategy for Sustainability, it is therefore timely and reasonable to consider how aspects of the system could be simplified and streamlined, without losing the hard-earned benefits to human health and the environment.
In this commentary, we propose a conceptual framework that could be the basis of Chemicals 2.0 – a future safety assessment and management approach that is based on the application of New Approach Methodologies (NAMs), mechanistic reasoning and cost-benefit considerations. Chemicals 2.0 is designed to be a more efficient and more effective approach for assessing chemicals, and to comply with the EU goal to completely replace animal testing, in line with Directive 2010/63/EU.
We propose five design criteria for Chemicals 2.0 to define what the future system should achieve. The approach is centered on a classification matrix in which NAMs for toxicodynamics and toxicokinetics are used to classify chemicals according to their level of concern. An important principle is the need to ensure an equivalent, or higher, protection level.
•There is a need to assess and manage chemicals more efficiently and effectively.•Chemicals 2.0 is a vision for a future safety assessment and management framework.•We propose five design criteria for Chemicals 2.0•NAM-based toxicodynamic and toxicokinetic data classify chemicals in concern levels.•A multi-stakeholder collaboration would develop the approach and build confidence.
•Testing of chemicals does not always inform their subsequent risk management.•Optimised testing strategies can improve efficiency of classification and labelling.•Hazard pictograms were used to ...reflect the protection level for a given chemical.•Two strategies led to the same protection level and required fewer tests.•Another strategy led to the same protection level and reduced animal testing.
This paper outlines a new concept to optimise testing strategies for improving the efficiency of chemical testing for hazard-based risk management. While chemical classification based on standard checklists of information triggers risk management measures, the link is not one-to-one. Toxicity testing may be performed with no impact on the safe use of chemicals . Each hazard class and category is not assigned a unique pictogram and for the purpose of this proof-of-concept study, the level of concern for a chemical for the population and the environment is simplistically considered to be reflected by the hazard pictograms. Using active substances in biocides and plant protection products as a dataset, three testing strategies were built with the boundary condition that an optimal approach must indicate a given level of concern while requiring less testing (strategy B), prioritising new approach methodologies (strategy C) or combining the two considerations (strategy D). The implementation of the strategies B and D reduced the number of tests performed by 6.0% and 8.8%, respectively, while strategy C relied the least on in vivo methods. The intentionally simplistic approach to optimised testing strategies presented here could be used beyond the assessment of biocides and plant protection products to gain efficiencies in the safety assessment of other chemical groups, saving animals and making regulatory testing more time- and cost-efficient.
Novel chemical hazard characterisation approaches Benfenati, Emilio; Berggren, Elisabet; Fritsche, Ellen ...
EFSA journal,
June 2016, 2016-06-00, 20160601, 2016-06-01, Letnik:
14, Številka:
S1
Journal Article
Recenzirano
Odprti dostop
There is a fundamental change in thinking within the regulatory community due to a better understanding of the underlying biology of adverse effects to human health and the environment. The ...development of alternatives to use laboratory animals has become a priority. In addition, technological progress is impacting greatly on the amount of data available and on the ways to process and analyse it. Topics, such as identification of adverse outcome pathways (AOPs) and modes of action (MoA), together with integrated assessment and testing approaches (IATAs), represent fundamental tools for hazard identification and characterisation of a chemical. Complex endpoints cannot be predicted by a single standalone non‐animal test; thus, a major challenge is the complex nature of biological systems. Microphysiological systems (MPS) will enable more complex in vitro human models that better simulate the organ's biology and function by combining different cell types in a specific three‐dimensional configuration that simulates functional organs. The process of validation of new approaches needs to be considered in terms of efficiency and length. Regulators might still not have enough confidence to adopt and apply these new approaches: this phase is very challenging and the activities performed by assay developers are not yet addressing the regulatory requirements needs sufficiently. The IATAs provide a framework to consistently evaluate new approach data and could assist in understanding their relevance for specific endpoints. The data need to be reproducible, understandable and statistically sound: indeed, a major issue lies in the interpretation and integration of the results based on subjective assessment, which relies on expert judgement. A well‐defined mechanistic characterisation is proposed as a way forward to ensure the relevance of new cell‐based test systems.
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