Regular use of sunscreens has been shown to reduce the risk of sunburn and skin cancer, and slow photoaging of skin. Sunscreens can rinse off into water where people are swimming or wading, and can also enter bodies of water through wastewater such as from bathing or showering. As a result, the ultraviolet (UV) filters – the active ingredients in sunscreens that reduce the amount of UV radiation on skin – have been detected in the water, sediment, and animal tissues in aquatic environments. Because the impact of these filters on aquatic ecosystems is not fully understood, assessment is needed to better understand their environmental impacts.This report calls on the U.S. Environmental Protection Agency to conduct an ecological risk assessment of UV filters to characterize the possible risks to aquatic ecosystems and the species that live in them. EPA should focus on environments more likely to be exposed such as those with heavy recreational use, or where wastewater and urban runoff enter the water. The risk assessment should cover a broad range of species and biological effects and could consider potential interacting effects among UV filters and with other environmental stresses such as climate change. In addition, the report describes the role of sunscreens in preventing skin cancer and what is known about how human health could be affected by potential changes in usage. While the need for a risk assessment is urgent, research is needed to advance understanding of both risks to the environment from UV filters and impacts to human health from changing sunscreen availability and usage.