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Polydimethylsiloxane (PDMS)

  • Silicones
  • CAS 63148-62-9
  • IUPAC: Poly(dimethylsiloxane)

Polydimethylsiloxane (PDMS) (CAS 63148-62-9) appears in 50 of the 1,812 car-care products CarCareTruth tracks (as of June 2026).

PDMS has very low acute toxicity. Oral LD50 in rats is >17 g/kg. Classified as a mild eye and skin irritant at high concentrations. Not a carcinogen, not a reproductive toxin, not a respiratory sensitizer. The linear form (PDMS) does not share the PBT/vPvB concerns of cyclic siloxanes (D4, D5).

Polydimethylsiloxane is a linear silicone polymer widely used in automotive protectants, personal care products, and industrial applications. In car care, PDMS forms a thin, non-greasy protective film on interior and exterior surfaces — plastic, vinyl, rubber, fiberglass — that provides UV screening and a matte or satin finish. It is distinct from cyclic siloxanes (D4/D5), which carry bioaccumulation and aquatic toxicity concerns under EU REACH regulation. PDMS is considered one of the safer silicone compounds for leave-on consumer products, with very low acute toxicity and no known endocrine-disrupting properties.

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: Linear silicone polymer — forms a protective, non-greasy film on plastics, vinyl, and rubber. Provides UV screening and surface conditioning without the greasy residue of silicone oils.

Common questions about Polydimethylsiloxane (PDMS)

What is Polydimethylsiloxane (PDMS) used for in car care?
Linear silicone polymer — forms a protective, non-greasy film on plastics, vinyl, and rubber. Provides UV screening and surface conditioning without the greasy residue of silicone oils.
Is Polydimethylsiloxane (PDMS) a VOC?
No. Polydimethylsiloxane (PDMS) is not classified as a volatile organic compound (VOC).
Is Polydimethylsiloxane (PDMS) on California's Proposition 65 list?
No. Polydimethylsiloxane (PDMS) is not on California's Proposition 65 list.

50 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.