The key ingredients in laundry detergent are surfactants, building and bulking agents, bleaches and optical brighteners, according to the Environmental Protection Agency. Surfactants and bleaches perform dirt and stain removal. Some detergents also include enzymes that break down organic stains. Chemical stabilizers, de-caking agents and solvents are also found in detergents.
Surfactants are compounds with regions of both positive and negative charge. These compounds dissolve dirt molecules and carry them away from the surfaces being cleaned. In conjunction with enzymes, which break down protein-based stains, surfactants are the primary cleaning agents in all laundry detergents.
Bleaches and optical whiteners enhance the appearance of laundered items but do not technically remove dirt or stain molecules from the fabric. Bleaches are strong, oxidizing chemicals that react with stain molecules and render them colorless. Optical whiteners enhance the perceived whiteness of clean fabrics by transforming ultraviolet waves to minimize yellow frequencies and maximize white frequencies.
Non-reactive building and bulking agents constitute most of the actual mass of powdered laundry detergents. The bulk of liquid detergents consists of water, which acts to dissolve all other components of the detergent. Binding agents ensure that the components of the detergent remain well mixed. Natural and artificial fragrances confer a pleasant scent to the detergent and the resultant clean clothes.