Environmental Risk Assessment of Technical Mixtures Under the European Registration, Evaluation, Authorisation and Restriction of Chemicals—A Regulatory Perspective
Authors: Galert Wiebke , Hassold Enken 
Published: January 2021

Abstract
The European Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation has been in force since 2007 and is intended to ensure a high level of protection for human health and the environment. The REACH regulation is based on the principle that manufacturers, importers, and downstream users take responsibility for their chemicals. Currently about 23 000 single chemicals are registered within the REACH legislation. A large proportion of substances registered under REACH end up in technical mixtures, intentionally manufactured as such, or generated mixtures containing byproducts of processes. Such mixtures that contain a number of different components are, for example, ink, paint, lacquer, mortar, or cleaning agents. However, REACH focuses on single substances and addresses the safe use of substances as such (e.g., bisphenol A) or substances in mixtures (e.g., bisphenol A used as an antioxidant in mixtures) and in articles (e.g., bisphenol A used as a monomer for polycarbonate production from which greenhouse sheets may be made). In contrast to other substance regulations, under REACH the registrants and downstream users of chemicals are responsible for the risk assessment. According to the REACH regulation, they also have the obligation to derive and communicate safe use conditions for their technical mixtures. Currently, no guidance document and no distinct obligations for an assessment of technical mixtures exist. In light of the available evidence for the joint exposures and effects of chemicals due to co-exposures, the need for approaches for a mixture assessment and improved data communications were highlighted by various stakeholders from industry, European member states, and the European Chemicals Agency (ECHA). The lead component identification (LCID) methodology and the safe use of mixtures information (SUMI) tool were proposed by the European Chemical Industry Council (Cefic) as working tools for the evaluation of the hazard potential, derivation of safe use conditions, and data communication for mixtures along the supply chain. The present paper analyzes the workability and pitfalls of these proposed methodologies from a regulatory perspective, aiming at a safe use of technical mixtures which considers the joint effects and exposures of its components. Integr Environ Assess Manag 2021;17:498–506. © 2021 Umweltbundesamt. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)
KEY POINTS
A large proportion of substances registered under the European Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation end up in technical mixtures, intentionally manufactured as such, or generated mixtures containing byproducts of processes; however, REACH focuses on single substances. More dialogue between stakeholders may strengthen data communication between registrants and downstream users, and uniform reporting templates and automated data forwarding and storage should help make data available and ensure quality of the data. Several weak points for the environmental matters were detected like the concentration depending cutoff of substances for the environmental hazard, leading to underestimation of risks for the environment.