Ammonium Hydroxide

Ammonium hydroxide is the active ingredient that distinguishes "ammonia-based" glass cleaners from "ammonia-free" alternatives. In Windex Original and similar formulations it appears at consumer dilution, where it acts as a surfactant booster and grease-cutter without classifying the mixture as DANGER under GHS. SC Johnson names it in its WhatsInside disclosure but publishes no concentration; professional-channel sheets for the same ready-to-use formula family place it below 0.1%, and the concentrate at 0.1 to 1.5%.

Compatibility concern

Ammonia attacks the adhesive layer of aftermarket window tint film over repeated use and can degrade hydrophobic glass coatings (RainX, ceramic glass coatings). For consumer automotive use, ammonia-free alternatives are preferred when the user has aftermarket tint or treated glass. Factory-embedded tint (the kind built into the glass during manufacturing) is unaffected because there is no adhesive layer.

Why it sometimes doesn't appear in the SDS

At consumer dilution, the ammonia concentration may fall below the GHS classification threshold for the mixture, even though the ingredient is present. SC Johnson's whatsinsidescjohnson.com ingredient disclosure confirms ammonium hydroxide in Windex Original; the corresponding US SDS classifies the mixture as "not hazardous." Both are accurate under their respective regulatory frameworks. For health and surface-compatibility scoring, the ingredient disclosure is the authoritative chemistry signal.

Related: Is Glass Cleaner Toxic? Read the full SDS breakdown of the car glass cleaners this base is the ammonia in.