This month marks 4 years since the Toxic Substances Control Act, or TSCA, was revised to boost confidence in chemical safety in the US by strengthening regulations. The updated law gave the Environmental Protection Agency sweeping new authority to ensure that the tens of thousands of chemicals in everyday products do not pose unreasonable risks to human health and the environment. In this bonus episode of Stereo Chemistry, host Kerri Jansen and C&EN senior reporter Britt Erickson examine how the EPA is using that authority to evaluate new chemicals before they hit the market and to assess the risks of chemicals that have been in use for decades. Is the EPA protecting public health by sufficiently evaluating the risks of chemicals, or is it giving industry a free pass to market chemicals with little toxicity data? A script of this episode is available at bit.ly/2UTlD8F. Image credit: Barry Barnes/Shutterstock