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CarCareTruth

Dimethicone (PDMS)

  • Silicones
  • CAS 9006-65-9
  • IUPAC: Polydimethylsiloxane

Dimethicone (PDMS) (CAS 9006-65-9) appears in 18 of the 2,122 car-care products CarCareTruth tracks (as of August 2026).

Biologically inert. Used extensively in cosmetics and medical devices. No known health hazards at any concentration.

Dimethicone is the workhorse silicone in car care. It's the active ingredient in most UV protectants (303 Aerospace), tire dressings, and spray waxes. It creates a thin, optically clear film that blocks UV radiation and repels water.

Health-wise it's exceptional — completely inert, non-toxic, non-irritating. The only concern is environmental persistence: silicones don't biodegrade and accumulate in soil and sediment over decades. They're not toxic to aquatic life, but they don't go away either.

Health & environment profile

VOC
no
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
no
Biodegradable
no
Bioaccumulative
no
Persistent
yes
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
3/5
Purpose: Surface conditioning, UV protection, hydrophobic layer

Common questions about Dimethicone (PDMS)

What is Dimethicone (PDMS) used for in car care?
Surface conditioning, UV protection, hydrophobic layer
Is Dimethicone (PDMS) a VOC?
No. Dimethicone (PDMS) is not classified as a volatile organic compound (VOC).
Is Dimethicone (PDMS) on California's Proposition 65 list?
No. Dimethicone (PDMS) is not on California's Proposition 65 list.

18 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.