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CarCareTruth

Hexamethyldisiloxane

  • Silicones
  • CAS 107-46-0
  • IUPAC: hexamethyldisiloxane

Hexamethyldisiloxane (CAS 107-46-0) appears in 3 of the 2,122 car-care products CarCareTruth tracks (as of August 2026). It is classified as a VOC.

Low acute toxicity. Flash point 4°C (flammable liquid Cat 1 at pure form). At <1% in finished formulations, acute hazard contribution is minimal. No skin sensitizer or respiratory sensitizer classification. GHS02 hazard is from flammability of the neat compound.

Hexamethyldisiloxane (HMDS, CAS 107-46-0) is a low-molecular-weight linear silicone solvent used in trace amounts in coating formulations as a carrier and diluent. It is more volatile than the high-molecular-weight cyclosiloxanes such as D5.

Health: Pure form is a flammable liquid (flash point 4°C). At <1% concentrations in a formulation, flammability hazard contribution is negligible. No GHS skin or respiratory sensitizer classification.

Environment: Moderate concern as a VOC in some jurisdictions. Not classified as bioaccumulative or aquatically toxic at trace concentrations. Lower environmental persistence than D5 due to faster environmental breakdown of linear vs. cyclic siloxanes.

Health & environment profile

VOC
yes
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
no
Biodegradable
no
Bioaccumulative
no
Persistent
no
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
4/5
Purpose: Low-molecular-weight silicone carrier and diluent in ceramic coating and silicone formulations

Common questions about Hexamethyldisiloxane

What is Hexamethyldisiloxane used for in car care?
Low-molecular-weight silicone carrier and diluent in ceramic coating and silicone formulations
Is Hexamethyldisiloxane a VOC?
Yes. Hexamethyldisiloxane is classified as a volatile organic compound (VOC).
Is Hexamethyldisiloxane on California's Proposition 65 list?
No. Hexamethyldisiloxane is not on California's Proposition 65 list.

3 products contain this

Related

Health and environment notes translate the manufacturer Safety Data Sheet, the GHS classification, and authoritative regulatory listings (California Prop 65, EPA). Not medical advice. They describe the ingredient itself; whether a hazard applies to a finished product depends on its concentration and how it's used.