Include a mixture allocation factor to improve EU chemical risk management.

Humans and ecosystems are continuously exposed to complex mixtures of chemicals (1). This issue of "chemical cocktails" has been receiving increasing attention by policy-makers and the public alike. Yet, the potential health and ecological impacts of coincidental mixtures of chemicals that combine in our bodies, and in wildlife, water, sediments, and soil from many sources, receive insufficient attention in chemical risk assessment and management. Instead, regulatory risk assessment primarily evaluates individual substances, and chemical products that might contain intentional mixtures or substances of unknown or variable composition. This gap results in a systematic underestimation of the risks for human health and the environment. As policy-makers in the European Union (EU) undertake a revision of the Regulation on the Registration, Evaluation, Authorization and Restriction of chemicals (REACH), they should incorporate a mixture allocation factor to enable more realistic chemical management and create incentives for safe and sustainable innovation without imposing undue administrative burdens. [ABSTRACT FROM AUTHOR]