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CarCareTruth

Disodium Metasilicate

  • Bases
  • CAS 6834-92-0
  • IUPAC: disodium dioxido(oxo)silane

Disodium Metasilicate (CAS 6834-92-0) appears in 9 of the 2,122 car-care products CarCareTruth tracks (as of August 2026). It is readily biodegradable.

At concentrated form, disodium metasilicate is corrosive (H314) and can cause serious respiratory irritation (H335). At the typical in-product concentration of 0–0.5% in consumer cleaners, the mixture-level hazard is reduced to WARNING/H315/H335. Strongly alkaline (pH 11–13 in solution). Not on California Prop 65 list.

Disodium metasilicate is an inorganic alkaline salt used as a builder in hard-surface cleaners, degreasers, and specialty automotive cleaners. It raises solution pH substantially — solutions containing it range from pH 11 to 13 depending on concentration — which is the mechanism behind its cleaning power (alkaline hydrolysis of greases and oils).

At product concentrations of 0–0.5%, the compound is dilute enough that the finished product typically receives a WARNING signal word rather than DANGER, though the pH remains significantly above neutral (11–12 range). This pH is outside the leather-safe range of 4.5–7.0, making it a relevant consideration for leather care products despite the low active concentration.

The compound is not a VOC, has no Prop 65 listing, and is considered environmentally benign in terms of persistence and aquatic toxicity at diluted concentrations.

Health & environment profile

VOC
no
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
no
Biodegradable
yes
Bioaccumulative
no
Persistent
no
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
3/5
Purpose: Alkaline builder used in cleaners; raises solution pH to improve soil removal; provides metasilicate-based cleaning action

Common questions about Disodium Metasilicate

What is Disodium Metasilicate used for in car care?
Alkaline builder used in cleaners; raises solution pH to improve soil removal; provides metasilicate-based cleaning action
Is Disodium Metasilicate a VOC?
No. Disodium Metasilicate is not classified as a volatile organic compound (VOC).
Is Disodium Metasilicate on California's Proposition 65 list?
No. Disodium Metasilicate is not on California's Proposition 65 list.
Is Disodium Metasilicate biodegradable?
Yes. Disodium Metasilicate has a confirmed biodegradable profile.

9 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.