Consumers and workers are generally exposed to multiple allergens and irritants simultaneously in products. This systematic review of 13 studies: 4 clinical, 6 animal, and 3 in vitro studies, suggests that co-exposure often enhances both sensitisation and elicitation reactions. When an irritant is combined with an allergen, the threshold for sensitisation and elicitation is lowered, and the severity of reactions is increased. Animal models suggest that weak allergens, when combined, can elicit responses at individual subthreshold doses, supporting their role as immune-enhancing adjuvants. Current regulations generally assess allergens or irritants in isolation, potentially overlooking the combined effects of low-level exposures from everyday products. There is a need to refine safety standards and ensure that risk assessment tools reflect real-world interactions between multiple allergens and irritants. Contact allergy is frequent and increasing in the population. A clearer understanding of mixture effects in sensitisation and elicitation responses is essential to protect the general population from developing contact allergy.

The EU recently introduced four new hazard classes to the Classification, Labelling and Packaging Regulation (CLP) (EC) 1272/2008. The classes are endocrine disruption for human health (ED HH) and the environment (ED ENV), persistent, bioaccumulative and toxic (PBT) or very persistent and very bioaccumulative (vPvB), and persistent, mobile and toxic (PMT) or very persistent and very mobile (vPvM). This action was a direct consequence of the EU’s Chemicals Strategy for Sustainability, which aims at strengthening the protection of human health and the environment, as well as reinforcing the CLP Regulation as the central piece of the chemicals legislation. This study examined the regulatory obligations triggered by these new hazard classes, as well as the existing obligations for endocrine disrupters and PBT/vPvB substances identified in other EU regulations. In addition, we compared the CLP criteria for endocrine disruption and PBT/vPvB to criteria existing in other EU regulations and investigated how these criteria are used in the EU chemicals legislation. We found that the implementation of the new hazard classes under the CLP into existing EU chemicals legislation will require the revision of all regulations that rely on the CLP hazard criteria for risk management. Without revision, the immediate impact of the new hazard classes will only extend to six regulations and the regulatory obligations they contain, all of which apply to substances classified under any of the CLP hazard classes. Meanwhile, substances with endocrine disrupting and PBT/vPvB properties are already being identified and regulated using criteria from regulations other than the CLP. When comparing the criteria for identification of endocrine disrupters and PBT/vPvB substances across the chemicals legislation, we found that the criteria differed between regulations. The findings aim to support the efficient implementation of the new CLP hazard classes and harmonization of criteria across regulations, in line with the Chemicals Strategy for Sustainability.

Background: Despite legislation aimed to protect the population against skin sensitization in the European Union (EU), over one quarter of the general population is sensitised to at least one chemical. Objectives: To provide an overview and comparison of European legislation concerning skin sensitization. In addition, we gathered the opinions of experts and stakeholders regarding improvements in the legislation and risk assessment process in the EU, to provide suggestions for improvement. Methods: Legislation was identified and compared. Four questionnaires were created towards industry, competent authorities and regulators, researchers/clinicians, and non-governmental organisations. The questions concerned the legislation, the risk assessment process, data collection and potential improvements. Results: Seven areas of legislation were analysed. The legislation was found to be unharmonised, for example, differing modes of restriction and accepted tests for skin sensitization. Approximately 40% of the questionnaire respondents found that the EU legislation and tools were not sufficiently protective. To improve the legislation 83% suggested harmonisation and 68% suggested better data sharing. Other areas were: improved exposure data (78%), better understanding of the skin sensitization mechanism (67%) and non-animal tests (66%). Conclusions: Stakeholders had varying confidence towards the protection of European citizens against skin sensitization. Multiple areas for improvement regarding the legislations and the risk assessment process were identified.

Chemicals in the EU are mainly regulated based on their intended use. Each legal framework consists of requirements and guidance for hazard- and risk assessment, along with the associated decision processes e.g., registration or authorisation of chemicals for market access in the EU. As a single chemical may have multiple uses, it may be assessed under more than one framework, potentially leading to different assessment outcomes. To address this, the European Commission has introduced the ‘one substance, one assessment’ approach as part of the Chemicals Strategy for Sustainability. The aims of the approach include streamlining risk assessment processes and reducing duplication of work in assessing the same chemical. This study aimed to map the scope of chemicals subject to assessment in multiple legal frameworks and to illustrate the importance of coordination and communication in chemical assessment processes. This was achieved by identifying chemicals that are either registered or have received specific approval for the EU market, and analysing their presence in different legal frameworks. Our findings showed that almost one-tenth of the substances identified were listed under more than one framework. However, there was a notable lack of coherent chemical identifiers available to accurately identify chemicals across the frameworks. Additionally, we identified the presence of phthalates, bisphenols and PFAS in EU frameworks to illustrate how a group-based approach to chemical assessment could be applied across different legal frameworks.

The CLP mandates manufacturers and importers to classify substances and mixtures according to hazard criteria, with notifications submitted to the European Chemicals Agency (ECHA). Substances meeting hazard criteria must be appropriately labelled and packaged to communicate hazards effectively. The CLP establishes hazard classification criteria but does not independently prohibit or restrict the use of hazardous chemicals. Instead, it serves as a basis for regulatory obligations in other specific regulations. This study investigates the regulatory implications of meeting hazard criteria under the CLP across EU regulations and directives listed in EU Chemicals Legislation Finder (EUCLEF). The results show that fulfilling criteria for human health hazard classes trigger regulatory obligations in the highest number of regulations/directives, with carcinogenicity, mutagenicity, and reproductive toxicity (CMR) leading to obligations in 19 of 20 pieces of legislation linked to the CLP. Conversely, physical, environmental, and ozone layer hazards are associated with fewer regulations and directives, and lead to fewer prohibitions. The study underscores the pivotal role of the CLP in EU chemical legislation and the need for coherence and consistency across regulations. While regulatory obligations are primarily aimed at substances meeting hazard criteria, the variability in self-classification notifications and limitations in harmonized classification processes were observed. Moreover, the complexity of the regulatory structure poses challenges for stakeholders and policymakers, including inconsistencies, compliance difficulties, and the need for frequent revisions. Addressing these challenges is critical for enhancing regulatory effectiveness and ensuring a more coherent and harmonized approach to chemical management in the EU.

The essential use concept aims to better protect consumers, vulnerable groups, and the environment from the most harmful chemicals by phasing out uses considered non-essential for society. Given the lack of empirical research evaluating this novel approach for chemical management in real-world settings, the aims of the present analysis were to 1) investigate if the information provided in applications for authorisation under REACH allowed for the identification of non-essential uses of substances of very high concern (SVHCs), and 2) identify data gaps, challenges and potential needs for revising the assessment criteria to effectively implement the essential use concept in the REACH authorisation. In total, 100 uses covering 11 SVHCs were analysed. 4-(1,1,3,3-tetramethylbutyl) phenol (OPnEO) and chromium trioxide were among the most frequently used substances, covering 42% and 35% of the analysed uses. Using the current essential use criteria, 55% of all analysed uses were categorised as essential, while 10% were categorised as non-essential. Potentially, authorisations would not have been granted for the identified non-essential uses under REACH if the concept had been implemented at the time. However, for 35% of the uses it was not possible to assess their essentiality and these uses were therefore categorised as “complex.” These challenges were due to the multiple purposes of the technical function, lack of detailed information on the spectrum of end-uses, and difficulties in interpreting the essential use criteria. Consequently, for a successful implementation of the essential use concept, we recommend the European Commission to develop guidance for applicants and refine the essential use criteria to ensure a transparent and resource-efficient authorisation procedure under REACH.

The EU Cosmetic Products Regulation requires neither environmental data nor environmental risk assessment for individual ingredients or finished cosmetic products. Instead, it relies on REACH to address environmental risks linked to cosmetic ingredients, including preservatives. We investigated how the environmental risks of cosmetic preservatives are managed by REACH. We identified preservatives of environmental concern and examined if any of these had been selected for Substance Evaluation, proposed for or identified as an SVHC, required authorization or were proposed for, or subject to, restriction under REACH. More than half of the preservatives approved under the Cosmetic Product Regulation, 70 of 137, were identified as being of environmental concern according to the criteria set in this study. Some of the approved preservatives were no longer produced or used in the EU due to their hazardous properties. However, they remained approved and may still enter the EU via the imported products. Our results also indicate that the environmental aspects of cosmetic ingredients, including preservatives, are not efficiently managed by REACH. Besides the known issues in REACH, we identified additional areas in the interface between REACH, CLP and the Cosmetic Products Regulation that call for improvement. Here, we provide practical suggestions in line with the Chemicals Strategy for Sustainability. If implemented, these measures would strengthen the protection of the environment from hazardous cosmetic ingredients.

This work presents a case study in applying a systematic review framework (SYRINA) to the identification of chemicals as endocrine disruptors. The suitability and performance of the framework is tested with regard to the widely accepted World Health Organization definition of an endocrine disruptor (ED). The endocrine disrupting potential of triphenyl phosphate (TPP), a well-studied flame retardant reported to exhibit various endocrine related effects was assessed. We followed the 7 steps of the SYRINA framework, articulating the research objective via Populations, Exposures, Comparators, Outcomes (PECO) statements, performed literature search and screening, conducted study evaluation, performed data extraction and summarized and integrated the evidence. Overall, 66 studies, consisting of in vivo, in vitro and epidemiological data, were included. We concluded that triphenyl phosphate could be identified as an ED based on metabolic disruption and reproductive function. We found that the tools used in this case study and the optimizations performed on the framework were suitable to assess properties of EDs. A number of challenges and areas for methodological development in systematic appraisal of evidence relating to endocrine disrupting potential were identified; significant time and effort were needed for the analysis of in vitro mechanistic data in this case study, thus increasing the workload and time needed to perform the systematic review process. Further research and development of this framework with regards to grey literature (non-peer-reviewed literature) search, harmonization of study evaluation methods, more consistent evidence integration approaches and a pre-defined method to assess links between adverse effect and endocrine activity are recommended. It would also be advantageous to conduct more case studies for a chemical with less data than TPP.

Background In the European Union (EU), the safety assessment of plant protection products relies to a large extent on toxicity studies commissioned by the companies producing them. By law, all performed studies must be included in the dossier submitted to authorities when applying for approval or renewal of the active substance.

Methods For one type of toxicity, i.e. developmental neurotoxicity (DNT), we evaluated if studies submitted to the U.S. Environmental Protection Agency (EPA) had also been disclosed to EU authorities.

Results We identified 35 DNT studies submitted to the U.S. EPA and with the corresponding EU dossiers available. Of these, 9 DNT studies (26%) were not disclosed by the pesticide company to EU authorities. For 7 of these studies, we have identified an actual or potential regulatory impact.

Conclusions We conclude that (1) non-disclosure of DNT studies to EU authorities, in spite of clear legal requirements, seems to be a recurring phenomenon, (2) the non-disclosure may introduce a bias in the regulatory risk assessment, and (3) without full access to all performed toxicity studies, there can be no reliable safety evaluation of pesticides by EU authorities. We suggest that EU authorities should cross-check their data sets with their counterparts in other jurisdictions. In addition, applications for pesticide approval should be cross-checked against lists of studies performed at test facilities operating under Good Laboratory Practice (GLP), to ensure that all studies have been submitted to authorities. Furthermore, rules should be amended so that future studies should be commissioned by authorities rather than companies. This ensures the authorities’ knowledge of existing studies and prevents the economic interest of the company from influencing the design, performance, reporting and dissemination of studies. The rules or practices should also be revised to ensure that non-disclosure of toxicity studies carries a significant legal risk for pesticide companies.