When the United States first regulated industrial chemicals in the 1970s, policy-makers made a threshold decision: Rather than a “front-end” approach requiring proactive risk assessment before licensing a chemical for use, Congress chose a reactive approach of regulating chemical risks as they became manifest (1). This choice puts a premium on “back-end” research on exposure pathways and hazards of new chemical contaminants in situ. Such research identifies contaminants in the environment, their source, where they go, and what harm they might cause (2). This knowledge is crucial for risk assessment and regulatory decisions. However, key features of the legislative design impede that essential research. Amid debate about how policymakers should apply existing scientific findings, these science-hindering features are easy to overlook. We highlight three of them: insufficient availability of chemical standards, limited public access to information, and excessive fragmentation of information within and among government agencies.