Flag of the United StatesAmerican Chemical Independence

Diethyl phenylphosphonite

CAS 1638-86-4

Phosphonous acid, P-phenyl-, diethyl ester

Molecular structure of 1638-86-4
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

CAS1638-86-4
PubChem CIDNot recorded
DTXSIDDTXSID8061840
FormulaC10H15O2P
Mol. Weight198.202 g/mol
SMILESCCOP(OCC)C1=CC=CC=C1

Data Sources

← Back to Dashboard

Brief citations

Diethyl phenylphosphonite (CAS 1638-86-4) https://chemicalindependence.com/chemical/1638-86-4/ EPA TSCA Inventory: CAS 1638-86-4. Retrieved 2026-10-04. https://www.epa.gov/tsca-inventory US Census international trade: HS 293149 for CAS 1638-86-4. Reporting year: 2024. https://usatrade.census.gov/