标题：A Chemical Category-Based Prioritization Approach for Selecting 75 Per- and Polyfluoroalkyl Substances (PFAS) for Tiered Toxicity and Toxicokinetic Testing
摘要：Per- and polyfluoroalkyl substances (PFASs) are a group of fluorinated substances of interest to researchers, regulators, and the public due
to their widespread presence in the environment. A few PFASs have comparatively extensive amounts of human epidemiological, exposure, and experimental
animal toxicity data (e.g., perfluorooctanoic acid), whereas little toxicity and exposure information exists for much of the broader set of
PFASs. Given that traditional approaches to generate toxicity information are resource intensive, new approach methods, including in vitro highthroughput
toxicity (HTT) testing, are being employed to inform PFAS hazard characterization and further (in vivo) testing. The U.S. Environmental
Protection Agency (EPA) and the National Toxicology Program (NTP) are collaborating to develop a risk-based approach for conducting PFAS toxicity
testing to facilitate PFAS human health assessments. This article describes the construction of a PFAS screening library and the process by which
a targeted subset of 75 PFASs were selected. Multiple factors were considered, including interest to the U.S. EPA, compounds within targeted categories,
structural diversity, exposure considerations, procurability and testability, and availability of existing toxicity data. Generating targeted HTT data
for PFASs represents a new frontier for informing priority setting.
