Sunscreens and a variety of other products contain chemical ultraviolet (UV) filters that absorb or block the sun's radiation and thereby help mitigate harms to human skin from the sun. The 2022 NASEM report Review of Fate, Exposure, and Effects of Sunscreens in Aquatic Environments and Implications for Sunscreen Usage and Human Health called on the EPA to conduct an ecological risk assessment of UV filters to characterize the possible risks to aquatic ecosystems and the species that live in them. However, the 2022 report also identified a number of knowledge gaps and research barriers that may limit understanding of those ecological risks.

To share progress and identify opportunities to further address gaps and barriers, NASEM hosted a workshop in Washington, D.C., on January 23?24, 2023, entitled Workshop to Advance Research on Understanding Environmental Effects of UV Filters in Sunscreens. Through a series of prepared talks, panel discussions, and structured breakout discussions, participants examined the 2022 report and its management context; explored data needs and analytical challenges relevant to the development of accurate toxicity metrics for UV filters; and suggested opportunities to improve and standardize toxicity testing for these chemicals. These proceedings has been prepared by the workshop rapporteur as a factual summary of what occurred at the workshop.