The Toxic Substances Control Act (TSCA) was enacted by Congress in 1976 and amended in 2016, and provides EPA authority to regulate certain new and existing chemicals commercialized in the United States for non-exempt purpose. Section 8(b) of TSCA requires EPA to compile, keep current, and publish a list of each chemical substance that is commercialized in the US for a TSCA use. 

The original TSCA Inventory was published in 1979 and included chemicals existing in US commerce at the time TSCA was first enacted. The second version, containing about 62,000 chemical substances, was published in 1982. The TSCA Inventory has continued to grow since then, it now contains 86,847 chemicals, of which 42,495 are active.