We investigated the numerous ways the chemical industry influences regulation of chemicals by the EPA and the FDA. Specifically, we discovered that industry-funded researchers have used a particular type of scientific study called “physiologically based pharmacokinetic (PBPK) modeling” to support industry claims that economically important chemicals are safe. We found that the scientists who pioneered PBPK modeling while working for the Air Force in the early 1980s had recognized early on that PBPK studies could be used to industry's advantage. As we examined the record over the past four decades, it became clear that these studies are primarily conducted by regulatory toxicologists working as private consultants or for research institutions funded by chemical companies. Further, these same individuals and consultancies often receive federal grants and contracts, suggesting widespread conflicts of interest. Our investigation documents the outcome - often delay or outright termination - of regulatory processes for numerous hazardous chemicals, including methylene chloride, formaldehyde, bisphenol A, perchlorate, styrene, and chlorpyrifos. While other journalists have documented the chemical industry's political influence, to our knowledge no other journalists have brought to light the ways science itself is being manipulated.