At an event at EPA headquarters in Washington, D.C., that was closed to the press, agency head Scott Pruitt touted the new policy as a way to increase transparency and enable the public to double-check research underpinning environmental regulations. The rule would require the agency to use only studies in which the underlying data are available for public scrutiny when formulating new “significant” regulations, which typically are regulations estimated to impose costs of $100 million or more. Specifically, the proposed rule says that EPA is seeking transparency for “the dose response data and models that underlie what we are calling...