Aminoethylaminopropyl Methyl Siloxane

Aminoethylaminopropyl methyl siloxane (CAS 71750-79-3) is the reactive ceramic active in many spray sealants and SiO₂ boosters from coating brands. The aminoethylamino side chains bond covalently to hydroxyl groups on the paint and glass surface, anchoring the silicone polymer backbone in place. The result is a thin hydrophobic film that tightens water beading and adds gloss without requiring a separate ceramic coating underneath. The chemistry is organosilicon, not fluoropolymer — no PFAS concerns. The amino-functional groups are mildly reactive, which is why the substance carries an H319 eye-irritation classification at neat strength. At the 3–7% concentration typical of consumer ready-to-use spray sealants, the amino reactivity is the only meaningful hazard pathway; no skin sensitization, no respiratory codes, no chronic-exposure codes apply. Aquatic toxicity is not classified at the substance level. The siloxane backbone is persistent in environmental compartments but with low ecotoxicological impact at the consumer use concentrations.