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Trioctylphosphine oxide

CAS 78-50-2

Phosphine oxide, trioctyl-

Molecular structure of 78-50-2
US productionNot reported
Import value, 2024$598M
Top sourceChina 89%

This chemical is listed as active in US commerce, but no company reported it to EPA’s survey for 2019 or 2023. Sites may have made or imported less than the threshold amount, or none.

Why supply is unknown

Production is reported production, not a complete census of factories. Import value and source-country shares describe a shared customs category, not a separate chemical measurement.

Where It Comes From

Customs basis: HS 293149 · basket

These shares come from HS customs code 293149, which covers 114 tracked chemicals in total. They estimate the category's origin mix, not this chemical specifically.

Source Countries
CN 89%ChinaIN 4%IndiaCA 3%CanadaDE 2%GermanyAR 1%Argentina

Why It Matters

No EPA sector or FDA product records name a use for this chemical.

Chemical Identity

CAS78-50-2
PubChem CIDNot recorded
DTXSIDDTXSID1052537
FormulaC24H51OP
Mol. Weight386.645 g/mol
SMILESCCCCCCCCP(=O)(CCCCCCCC)CCCCCCCC

Data Sources

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Brief citations

Trioctylphosphine oxide (CAS 78-50-2) https://chemicalindependence.com/chemical/78-50-2/ EPA TSCA Inventory: CAS 78-50-2. Retrieved 2026-10-04. https://www.epa.gov/tsca-inventory US Census international trade: HS 293149 for CAS 78-50-2. Reporting year: 2024. https://usatrade.census.gov/