Persistent, Mobile, Toxic: The Effects of Chemical Warning Labels on Public Risk Perception

Persistent, mobile, and toxic (PMT) chemicals, such as per- and polyfluoroalkyl substances (PFAS), pose significant environmental and health risks. Public risk perception is an important driver of change in regulation and consumption patterns. Previous research has investigated the effect of toxicity information, but little is known about public perception of chemical properties such as persistence or mobility alone or in combination with toxicity. In this study, 328 participants rated one of two everyday products in terms of affect, concern, and policy support. Labels indicated the presence of persistent (P), mobile (M), and toxic (T) chemicals either in isolation or combined (PM, PT, MT, and PMT), compared to a control with no label. When labels indicated only a single chemical property, toxicity elicited the strongest risk response, and this was amplified for products with high body contact (dental care) compared to low body contact (household cleaner). Labels warning of all three properties together (PMT) triggered the strongest risk response while demonstrating a nonadditive relationship. These findings suggest that the public is sensitive to warnings about different chemical properties beyond toxicity. Informing the public of diverse chemical properties has the potential to change behavior and encourage support for stricter regulation.