The Toxic Substances Control Act (TSCA) is a U.S. law that regulates the introduction of new or existing chemicals. It aims to ensure that chemicals used in manufacturing and products do not pose unreasonable risks to human health or the environment. The law requires companies to provide information about the chemicals they produce and use. Under TSCA, the Environmental Protection Agency (EPA) has the authority to assess and manage risks associated with chemical substances. This includes evaluating new chemicals before they enter the market and taking action on existing chemicals that may be hazardous.