EPA TSCA Chemical Substance Inventory

EPA TSCA Chemical Substance Inventory is the federal government's complete roster of chemical substances legally in United States commerce under section 8(b) of the Toxic Substances Control Act - and for Commodity Chemicals it is the master list of what can be sold at all. A substance on the inventory is an existing chemical; a substance off it is new, and manufacturing or importing it first requires a Premanufacture Notice. Every sourcing decision, every supplier qualification and every import declaration in bulk chemistry starts from this boundary.

The July 2026 edition carries 86,741 entries: 70,774 named, non-confidential listings - the workhorse acids, bases, solvents, monomers and salts that move by the tankard and the railcar - plus 15,967 companion records that identify confidential entries by accession number and generic name. Of the named listings, 36,522 are active in US commerce and 34,252 sit inactive, a near-half split that quietly reshapes any screen built without checking it. The statute's edges matter too: pesticides, drugs, foods, cosmetics, tobacco, nuclear materials and munitions live under other laws, so the inventory defines commodity chemistry by exclusion as much as by inclusion. Get a sample of this dataset scoped to the substances you actually buy and sell.

Three named listings and one confidential placeholder, straight from the July 2026 edition:

# TSCAINV -- NAMED NON-CONFIDENTIAL LISTINGS, JULY 2026 EDITION
casregno  casrn      chemname                                          uvcb  flag  activity
50000     50-00-0    Formaldehyde                                      -     -     ACTIVE
50011     50-01-1    Guanidine, hydrochloride (1:1)                    -     -     ACTIVE
50077     50-07-7    Azirino[2',3':3,4]pyrrolo[1,2-a]indole-4,7-di...  -     S     ACTIVE

# PMNACC -- CONFIDENTIAL ENTRIES, KEYED BY ACCESSION NUMBER
pmnno     accno      genericname                                       flag    activity
P000005   232689     Polymeric MDI based polyurethane (PROVISIONAL)    PMN; S  ACTIVE

# STATUS COUNTS, JULY 2026 EDITION
active in us commerce : 36,522 substances
inactive              : 34,252 substances
confidential entries  : 15,967 records
total inventory       : 86,741 entries

The texture tells you how to work with the data. Small molecules arrive clean: a dashed CAS number, a crisp index name, nothing else attached. Process-defined materials truncate mid-name because the CA index name runs long and the identity is a definition, not a formula. And roughly one entry in five surfaces only as a generic name pinned to an accession number - 15,967 of them - so a portfolio screen that ignores the companion table silently misses a fifth of the universe.

Eight columns do the analytical work on every named listing, typed and defined below. casregno and CASRN give the registry number with and without dashes - keep both, because half the tables you join against store it one way and half the other. ChemName carries the preferred CA index name; DEF supplies the chemical substance definition that separates two Class 2 substances sharing an index name; UVCB marks the unformulatable ones outright. FLAG stacks up the agency's regulatory action codes, ACTIVITY settles the active-versus-inactive question most screens start from, and EXP timestamps the statuses that lapse.

Records in the confidential companion table trade the chemical identity for a different set of handles - premanufacture notice number, accession number and generic name. Those ship as additional fields on request, mapped onto the same dictionary so one pipeline reads both tables.

• Geography: the United States - substances manufactured, processed or imported into US commerce, regardless of where production sits. An overseas plant shipping into American supply chains lands in the inventory just the same.
• Temporal: the current edition is the July 2026 snapshot of a compilation first published in 1979, and it grows one substance at a time as Notices of Commencement graduate new chemicals onto the existing list. Historical editions persist, so change-between-editions is a diffable question, not an archival hunt.
• Granularity: one row per substance listing - 70,774 named plus 15,967 confidential-entry records. There are no volumes, no companies and no plants: this is the universe of legal commodity chemistry, not who makes how much of it.

Scale check: 86,741 entries is small enough to hold entirely in memory and large enough that nobody reconciles it by hand - which is precisely the size where a flat, well-keyed table beats a portal.

API, files, or your warehouse. Daily, weekly, or hourly.

You choose the channel and the cadence; the field dictionary above travels unchanged across all three. Files suit compliance teams loading a full portfolio screen once a quarter, API payloads suit products that resolve a single CAS number inside an app or a formulation tool, and warehouse delivery suits teams running spend, sourcing and exposure analysis in SQL beside their own supplier tables. Changing cadence is a settings conversation, not a re-integration project.

• Procurement and sourcing teams qualify suppliers against the list before the contract, not after: a substance a vendor quotes that turns out inactive in US commerce is a very different negotiation than an established workhorse chemical.
• Regulatory and product-stewardship teams confirm existing-chemical status ahead of an import or a reformulation, and read the FLAG codes as the earliest structured signal of where agency attention is heading - section 6 risk management rules marked R, significant new use rules marked S, export prohibitions under 12C.
• Market analysts and consultants pair the substance universe with volume-side sources - Chemical Data Reporting manufacturing summaries, petrochemical feedstock series - to size segments from what may be traded to what actually is.
• Data scientists and ML engineers join CAS Registry Numbers into hazard, property and price models; the UVCB flag tells you which substances need fuzzy matching rather than an exact key.
• Journalists, academics and students cite the government's own boundary of American commercial chemistry - 86,741 entries with institutional custody behind every row.

Competitive-intel and product teams read the FLAG layer across a competitor's portfolio and see restriction pressure before it reaches a press release. Market researchers and consultants use the active/inactive split to bound any addressable-market estimate - 34,252 listed substances cannot be bought today, whatever the deck says. Developers and data-product builders stand compliance checkers, PIM systems and formulation tools on a stable eight-field registry keyed by CAS number. Investors and quants treat accumulating flags as regulatory-cost signal on feedstock-exposed names. Journalists, academics and students get citable provenance instead of an aggregator's guess.

Because the raw list arrives as a snapshot to be tamed: two tables with different shapes, registry numbers in two formats, index names that run past any column width, and a fifth of the universe speaking in accession numbers. We flatten both tables into the single dictionary above, normalize every identity to CAS number so joins never depend on spelling, flag which records came from the confidential side, and scope the extract to the substances on your watchlist instead of handing you all 86,741 rows and wishing you luck. Get a sample of this dataset built around your portfolio, then schedule deliveries at the cadence your compliance calendar actually runs on.

Notes that pair well with this page:

• Commodity Chemicals data hub - the pooled industry view this dataset sits inside, from reference constants to emission inventories.
• EPA Chemical Data Reporting (CDR) - the volume side of the same substances: who makes how much, for which industrial functions, cycle by cycle. Inventory says what may exist; CDR says what moves.
• EPA Toxics Release Inventory (TRI) - facility-level releases to air, water and land for the substances you screen.
• EPA ChemView - the per-substance dossier of studies, assessments and actions behind each flag code.
• NIST Chemistry WebBook - evaluated thermochemistry and spectra to attach physical constants to the same CAS keys.

Background reading: TSCA Chemical Substance Inventory and CAS Registry Number. Browse the vertical on the Commodity Chemicals industry hub or the ranked best commodity chemicals datasets.