Siloxane (Proprietary)
- Ceramic (SiO₂)
- CAS proprietary
- IUPAC: Siloxane (proprietary, CAS undisclosed)
Siloxane (Proprietary) (CAS proprietary) appears in 2 of the 1,812 car-care products CarCareTruth tracks (as of June 2026).
Carries H315 (Skin Irritation Cat 2), H318 (Serious Eye Damage Cat 1), and H335 (STOT SE 3 respiratory irritation) at ingredient level per SDS §3 — these translate to mixture-level classifications in this product's SDS §2.
This ingredient is a proprietary siloxane (CAS not publicly disclosed) that forms the active crosslinked protective film in Gtechniq EXO V4. Siloxane chemistry (Si–O–Si backbone) is the basis for the product's hydrophobicity and contamination repellency — the condensation cure reaction binds the siloxane matrix to the clear-coat surface to create a durable film.
The H318 (Serious Eye Damage Cat 1) classification at ingredient level transfers to the mixture-level SDS §2, driving the DANGER signal word and the eyes: required PPE tier for the product. Standard siloxane polymers are not PFAS (organosilicon, not organofluorine) and are not classified as aquatic toxicants at the concentrations used in consumer coatings. CAS number is not publicly disclosed by Gtechniq for this ingredient; classification data is derived from SDS §3 hazard codes.
Health & environment profile
- VOC
- no
- 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
Common questions about Siloxane (Proprietary)
- What is Siloxane (Proprietary) used for in car care?
- Proprietary siloxane active ingredient; forms the primary hydrophobic and protective film layer in polysilazane coatings via crosslinking and condensation on the clear-coat surface
- Is Siloxane (Proprietary) a VOC?
- No. Siloxane (Proprietary) is not classified as a volatile organic compound (VOC).
- Is Siloxane (Proprietary) on California's Proposition 65 list?
- No. Siloxane (Proprietary) is not on California's Proposition 65 list.
2 products contain this

Gtechniq EXO Crystal Hydrophobic Coatingceramic-coating
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.