Free TSCA Inventory search
TSCA Inventory lookup by CAS number
Search 70,774 substances on the EPA non-confidential TSCA Chemical Substance Inventory, July 2026 release. Every result carries its commercial activity status and its EPA regulatory flags, with what each flag actually obliges. Searching is free and needs no account.
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What this lookup can and cannot tell you
It searches the public portion only
EPA maintains a confidential portion of the Inventory that it does not publish. Those substances carry an accession number and a generic name instead of a CAS number, so no CAS search reaches them, here or anywhere else. A miss on this page means there is no public record. It is not a finding that the substance is unlisted, and treating it as one can mean filing a premanufacture notice you do not owe.
It reports flags, it does not interpret them for your use
A significant new use rule flag tells you a rule names the substance. Whether your particular use is a designated significant new use is settled by reading the relevant section of 40 CFR part 721, subpart E, not by this page.
It says which release it came from
EPA republishes the Inventory about every six months. Every answer here is from the July 2026 release, and says so.
Background reading: active and inactive designations, the XU flag, significant new use rules, and the PMN flag.