Cyclopentasiloxane, 2,4,6,8,10-pentamethyl-

CAS 6166-86-5

U.S. production volumes are classified as confidential business information.

US productionCBI

Confidential Business Information. The EPA withholds this volume because publishing it could reveal the reporting company's trade secrets.

Import value, 2024$537M

Top sourceChina 39%

At least one company claimed its 2023 production or import volume for this chemical as confidential, so EPA withholds it.

Why supply is unknown

Production is reported production, not a complete census of factories. US production volume is confidential. Production reporting year: 2023. Import value and source-country shares describe a shared customs category, not a separate chemical measurement.

Where It Comes From

Customs basis: HS 293190 · basket

EPA reports by year

2023: US production Confidential · Imports Confidential
2019: US production Confidential · Imports Confidential

These shares come from HS customs code 293190, which covers 378 tracked chemicals in total. They estimate the category's origin mix, not this chemical specifically.

Source Countries

Country of origin for US imports, from Census customs data (2024).

CN 39%ChinaDE 17%GermanyIT 9%ItalyIN 7%IndiaJP 7%Japan

Ireland
Netherlands
Switzerland
Monaco
Ukraine
Spain
Mexico
Poland
Indonesia
Armenia
Israel
Sweden
Australia
Czech Republic
Hungary
Brunei
Hong Kong
Brazil
Thailand
Argentina
Finland
Austria
Latvia

EPA-registered importers (1)

Companies that report making or importing this chemical to the EPA. Registration is US-centric and does not indicate import origin.

Dow Chemical

Why It Matters

Sectors

Core Chemicals

Downstream UsesNot recorded

FDA Shortage Status

Whether any manufacturer currently reports this drug as in shortage on the FDA Drug Shortages database. "Active Shortage" means at least one presentation has status "current."

No FDA shortage records

Industrial Uses

•Intermediate in All Other Basic Inorganic Chemical Manufacturing (10%)Processing—repackaging

Chemical Identity

CAS6166-86-5

PubChem CID6327588

DTXSIDDTXSID80871154

FormulaC5H15O5Si5

Mol. Weight295.59 g/mol

SMILESC[Si]1O[Si](O[Si](O[Si](O[Si](O1)C)C)C)C

Data Sources

EPA CompTox (DSSTox) · DTXSID80871154Retrieved 2026-04-06
PubChem · compound 6327588Retrieved 2026-04-06
EPA Chemical Data ReportingReporting year: 2023 · Retrieved 2026-10-04
EPA Chemical Data ReportingReporting year: 2023 · Retrieved 2026-10-04
US Census international tradeReporting year: 2024 · Retrieved 2026-10-04

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Brief citations

Cyclopentasiloxane, 2,4,6,8,10-pentamethyl- (CAS 6166-86-5) https://chemicalindependence.com/chemical/6166-86-5/ EPA CompTox (DSSTox): DTXSID80871154. Retrieved 2026-04-06. https://comptox.epa.gov/dashboard/chemical/details/DTXSID80871154 PubChem: 6327588. Retrieved 2026-04-06. https://pubchem.ncbi.nlm.nih.gov/compound/6327588 EPA Chemical Data Reporting: 6166-86-5. Reporting year: 2023. https://www.epa.gov/chemical-data-reporting EPA Chemical Data Reporting: CAS 6166-86-5. Reporting year: 2023. https://www.epa.gov/chemical-data-reporting US Census international trade: HS 293190 for CAS 6166-86-5. Reporting year: 2024. https://usatrade.census.gov/