Introduction

The group of chemicals termed per- and polyfluorinated alkyl substances (PFASs) has attracted much attention recently because of concerns regarding their ubiquitous environmental occurrence and their persistence. PFASs are termed “forever chemicals” as some forms are persistent in the environment and can bioaccumulate in organisms. Some PFASs have been detected in animal species in environments far from contaminated sites, supporting the need to understand the risk associated with exposure of valued wildlife species to PFASs. Here, we provide a review of the most recent toxicity information relevant to terrestrial wildlife, namely mammals, birds, reptiles, and amphibians, and use a comprehensive approach to developing toxicity benchmark values for screening and decision-making purposes. These toxicity reference values (TRVs) are intended to be useful in a risk assessment approach to evaluating risk at sites contaminated with PFAS and to serve as a reference point of the toxicity of certain PFASs when assessing risks to wildlife populations.