Octamethyltrisiloxane

Description

Octamethyltrisiloxane · CAS 107-51-7 · C8H24O2Si3. UNII 9G1ZW13R0G. Vapor Pressure: 3.34 [mmHg].

Identification

CAS Registry Number	107-51-7
PubChem CID	24705
Molecular formula	C8H24O2Si3
IUPAC name	dimethyl-bis(trimethylsilyloxy)silane
UNII (FDA)	9G1ZW13R0G

Computed Descriptors

Molecular Weight	236.53
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	4
Exact Mass	236.10840961
Monoisotopic Mass	236.10840961
Topological Polar Surface Area	18.5
Heavy Atom Count	13
Formal Charge	0
Complexity	149

Physical & Chemical Properties

Vapor Pressure	3.34 [mmHg]

Physical description & handling notes

• Liquid
• Liquid; [Merck Index] Colorless odorless liquid; [Acros Organics MSDS]

Regulatory Status

Regulatory & Food Contact	CIR / INCI: Skin conditioning
GHS notification summary	11.1% (49 / 443)

GHS Hazard Classification

GHS notification summary	11.1% (49 / 443)
Reported hazard statements	H226 (88.9%), H413 (27.1%)

Documented Uses

• Used as a base for extreme temperature silicone oils/fluids and as a foam suppressant in petroleum lubricating oils; [Merck Index] Used mainly to make polydimethylsiloxane (PDMS) polymers, oligomers, and mixtures; Also used to make basic chemicals, paints, coatings, adhesives, soaps, cleaning compounds, toiletries, plastics, semiconductors, and other electronic components, and in building construction, lubricants, diluents, solvents, and cosmetics; [Government of Canada - Chemicals Management Plan]
• Semiconductor Manufacturing [Category: Industry]
• Cosmetics product ingredient: Trisiloxane, octamethyl- (Octamethyltrisiloxane; Trisiloxane)
• Reason for Listing: Listed as Persistent, Bioaccumulative, and Inherently Toxic to the environment by the Canadian Environmental Protection Act Environmental Registry Domestic Substances List.
• Potential Health Impacts: Bioaccumulation, Environmental Persistence, and Undefined Toxicity
• 2023: 1,000,000 - <5,000,000 lb

Synonyms

OCTAMETHYLTRISILOXANE; 107-51-7; Trisiloxane, octamethyl-; 1,1,1,3,3,5,5,5-Octamethyltrisiloxane; dimethyl-bis(trimethylsilyloxy)silane; Pentamethyl(trimethylsilyloxy)disiloxane; DTXSID9040710; Dimethylbis(trimethylsiloxy)silane; 9G1ZW13R0G; Pentamethyl(trimethylsiloxy)disiloxane; CHEBI:9147; DTXCID7020710; RefChem:1093790; 203-497-4; Dimethicone 350; Simethicone Impurity 6

Frequently Asked Questions

What are the CAS number and molecular formula of Octamethyltrisiloxane?

CAS 107-51-7; molecular formula C8H24O2Si3; molecular weight — g/mol.

What other names is Octamethyltrisiloxane known by?

OCTAMETHYLTRISILOXANE, 107-51-7, Trisiloxane, octamethyl-, 1,1,1,3,3,5,5,5-Octamethyltrisiloxane, dimethyl-bis(trimethylsilyloxy)silane, Pentamethyl(trimethylsilyloxy)disiloxane.

What is the regulatory status of Octamethyltrisiloxane?

Documented regulatory listings: CIR / INCI: Skin conditioning.

Is Octamethyltrisiloxane classified as hazardous?

11.1% of GHS notifications report no hazard classification (49 of 443).

What are the key physical properties of Octamethyltrisiloxane?

Vapor Pressure: 3.34 [mmHg].

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.