Disodium Metasilicate

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.