Stain-removing products are used to clean a variety of surfaces and materials, including toilets, sinks, countertops, floors, glass and fabrics. Many of these products utilize an array of active ingredients with different chemical properties. Some of the most common active ingredients in stain removers include ammonia, bleach, enzymes and d-limonene.
Ammonia is a colorless alkali gas compound that is soluble in water. The alkaline state of ammonia solutions makes them effective at killing bacteria and other microorganisms, as well as breaking up stains. According to Clean Link, manufacturers most commonly use ammonia as an active ingredient in glass and window cleaners. However, it also is present in some floor waxes, oven cleaners and a variety of other cleaning products. Be careful when working with ammonia-based stain removers, as they can irritate the eyes and skin.
Bleach, also known as sodium hypochlorite, is a sterilizing and whitening chemical agent. It works by oxidizing (or stealing electrons from) the compounds comprising germs and stains, which effectively breaks down their molecular bonds. You can purchase bleach by the bottle, usually in a 5-percent solution, and use it to clean tubs, floors and fabrics, among other things. It also is the active ingredient in a number of stain-removing products. Avoid using bleach-based products in combination with acidic toilet bowl cleaners as they could inadvertently produce toxic chlorine gas.
According to the University of Nebraska, some manufacturers use protease enzymes in their stain-removing products. Enzymes are catalytic (or reaction-inducing) substances, which living organisms produce. Protease enzymes specifically help break down complex proteins, such as those comprising grass, soil, blood and food stains.
D-limonene is a neutral compound that manufacturers extract from the rinds of citrus fruits such as lemons, limes and oranges. While you can use pure d-limonene as a solvent for removing paints and oil-based stains, it also is found in commercial cleaning products. According to Clean Link, because of d-limonene's insolubility in water, manufacturers must first combine it with a surfactant, or a chemical that reduces its surface tension. This allows it to mix more easily with solutions (although it does not dissolve).