TSCA is the Toxic Substances Control Act, a law passed in 1976, which is administered by the US EPA and regulates chemical substances in commercial products—their production, import, use, and disposal. Certain chemicals are not regulated under TSCA-for example, food additives, drugs, cosmetics, and pesticides. Chemical substances are separated into “existing” chemicals (those on the TSCA Inventory) and “new” chemicals. The EPA has the authority to require reporting, record keeping, testing, and restrictions. The Office of Pollution Prevention and Toxics (OPPT) manages programs under TSCA. NTTC is the OPPT Tribal Partnership Group. You can find a summary of TSCA here.
In 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act was passed by Congress as an update to TSCA. The Lautenberg Act mandated EPA to evaluate existing chemicals based on their risks to human health and the environment and to eliminate any unreasonable risks that it finds. There is more information on this risk assessment process here. An important TSCA amendment under the Lautenberg Act, is the requirement for EPA to consider exposures and hazards to “potentially exposed or susceptible subpopulations”, as well as to take into account “the likely duration, intensity, frequency, and number of exposures” of each chemical substance. You can find more information on the Lautenberg Act here.