In 1976, the U.S. Congress passed the Toxic Substances Control Act (TOSCA). This act requires the premarket testing of toxic substances. When a chemical substance is planned to be manufactured, the producer must notify the Environmental Protection Agency (EPA), and, if the data presented is determined to be inadequate to approve its use, the EPA will require the manufacturer to conduct further tests. Or, if it is later determined that a chemical is present at a level that presents an unreasonable public or environmental risk, or if there is insufficient data to know the chemical’s effects, manufacturers have the burden of evaluating the chemical’s characteristics and risks. If testing does not convince the EPA of the chemical’s safety, the chemical’s manufacturing, sale, or use can be limited or prohibited.