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What is the TSCA Chemical Substance Inventory?

The Toxic Substances Control Act (TSCA) was enacted in 1976 to ensure that chemicals manufactured, imported, processed, or distributed in commerce, or used or disposed of in the United States do not pose any unreasonable risks to human health or the environment. Core regulatory provisions include TSCA section 4 (testing of chemical substances and mixtures), TSCA section 5 (manufacturing and processing notices), TSCA section 6 (regulation of hazardous chemical substances and mixtures), and TSCA section 8 (reporting and retention of information).

TSCA section 8(b) Exit EPA Disclaimer provides EPA authority to "compile, keep current, and publish a list of each chemical substance that is manufactured or processed in the United States." TSCA section 3(2)(A) states that "the term 'chemical substance' means any organic or inorganic substance of a particular molecular identity, including - (i) any combination of such substances occurring in whole or in part as a result of a chemical reaction or occurring in nature, and (ii) any element or uncombined radical." TSCA does not include chemical substances subject to other US statutes such as foods and food additives, pesticides, drugs, cosmetics, tobacco, nuclear material, or munitions.

EPA published the final TSCA Inventory Reporting Rule on December 23, 1977. The initial reporting period was January to May of 1978, for chemical substances in commerce since January of 1975. The initial TSCA Chemical Substance Inventory was published in 1979; a second version was published in 1982 (?) and included approximately 62,000 chemical substances provided to EPA during the initial and follow-up reporting periods. Through the addition of new chemicals in commercial TSCA applications in the US, there are more than 83,000 chemical substances, as defined in TSCA section 3(2)(A) - among them as organics, inorganics, polymers, and UVCBs (chemical substances of Unknown, or Variable composition, Complex reaction products, and Biological materials) - on the Inventory at this time.

How do I determine if a chemical substance is on the TSCA Inventory?

The official public distribution mechanism for the non-confidential data from the TSCA Inventory master file is the National Technical Information Service (NTIS). EPA does not provide searches of the non-confidential TSCA Inventory. To purchase a copy from NTIS:

The non-confidential listings from the TSCA Inventory master file are also available in paper from the Government Printing Office (GPO), however, this product was last updated in 1990 and therefore does not reflect additions to the Inventory since then. To purchase a paper copy from GPO:

Other sources of non-confidential TSCA Inventory data include EPA's Substance Registry System, an on-line chemical pointer system for EPA regulated or monitored substances. Please be advised, however, that the SRS currently is not updated as regularly as the NTIS product with respect to TSCA chemicals. In addition, several commercial services provide searches for the non-confidential Inventory for a fee. None of them is connected to or has a specific endorsement from EPA. As far as the Agency is aware, each uses the regularly-updated Inventory listings available from NTIS.

Companies with a genuine intent to manufacture or import specific chemical substances can obtain a written determination from EPA as to whether their substance matches the chemical identities of substances already on the TSCA Inventory master file (including those with confidential chemical identities) by submitting a Bona Fide Intent to Manufacture or Import Notice to the Agency.

What if a chemical is not on the TSCA Inventory?

Substances on the TSCA Inventory are considered "existing" chemicals in U.S. commerce, and substances not on the TSCA Inventory are "new" chemicals. The TSCA Inventory must be consulted to determine if a specific substance is "new" or "existing."

If a substance is determined to be a "new" chemical substance for TSCA purposes, it is subject to TSCA section 5 Premanufacture Notice (PMN) requirements, unless the substance meets a TSCA reporting exclusion (e.g., is a naturally-occurring material) or is exempt from PMN reporting (e.g., is an exempted polymer). For substances that are "existing" chemical substances in U.S. commerce, the TSCA Inventory can be used to determine if there are restrictions on manufacture or use.

In some cases, a manufacturer may be intending to use reactants whose specific chemical identities are held confidential by their suppliers. In certain other cases, a potential importer may be intending to bring into the U.S. a substance whose identity is known only to its foreign manufacturer. In these cases, a letter of support from the domestic or foreign manufacturer of the confidential substances can be provided directly to EPA and should include specific chemical identity information. When using a Branded Material of Confidential Composition users will need information from their suppliers to ensure that they are and remain in compliance.

How are chemicals added to the TSCA Inventory?

After PMN review has been completed, the company that submitted the PMN must provide a Notice of Commencement of Manufacture or Import (NOC) (EPA Form 7710-56) to EPA within 30 calendar days of the date the substance is first manufactured or imported for nonexempt commercial purposes. A chemical substance is considered to be on the TSCA Inventory and becomes an existing chemical as soon as a complete NOC is received by EPA. The Agency receives between 500 and 1,000 NOCs each year, thus the TSCA Inventory changes daily.

Non-PMN submissions (Low Volume Exemptions - LVEs, Low Release/Low Exposure Exemptions - LoREXs, Test Market Exemptions - TMEs) and exempt uses not subject to submission (R&D;) do not require an NOC and are not listed on the TSCA Inventory.

In considering use of an existing chemical, a user will need to determine whether the substance is subject to other rules under TSCA. For this, consult the Chemicals on Reporting Rules Database (CORR), available as an electronic database from the TSCA Hot Line. New rules that control use of a substance will be published in the Federal Register.


Since the initial TSCA Inventory was compiled in 1979, EPA has developed numerous policy statement and guidance documents on how to identify certain chemical substances for the purpose of assigning unique and unambiguous descriptions for each substance listed on the Inventory. These include:

Additionally, instructions for developing generic names for use in PMN submissions are found in TSCA Inventory, 1985 Edition, Appendix B: "Generic Names for Confidential Chemical Substance Identities (PDF) (4 pp, 477K, about PDF).


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