whiten

Whiten is a verb meaning to cause to become white or to become white. It can refer to removing color from a substance or lightening its hue. The noun whiteness denotes the property of being white or the appearance of whitened surfaces. Etymology: the term derives from Old English hwīt, "white," with the verbal suffix -en.

In color theory, white is the perception produced when light contains all visible wavelengths in roughly equal measure, or when pigments reflect light without imparting a hue. White surfaces reflect most light, contributing to a sense of brightness. In textiles and paper, whiteness is enhanced with white pigments such as titanium dioxide and with optical brighteners that increase perceived whiteness under illumination.

Whitening processes include chemical bleaching, mechanical whitening, and optical methods. Chemical bleaches such as chlorine-based sodium hypochlorite and peroxide-based agents oxidize colorants to make them colorless. Optical brighteners and blueing agents counteract yellowing by re-emitting blue light.

Applications span laundry and textiles (cleansing and whitening fabrics), paper manufacturing (bleaching pulp), wood processing (whitewashing), and dentistry and cosmetics (tooth whitening and skin products). The term also appears in everyday usage, as in whitening a shirt, whitening teeth, or whitening a surface.

Safety and limitations: bleaching agents can be corrosive or harmful if misused; whitening effectiveness depends on the underlying material, and some pigments or fabrics are not color-stable under whitening treatments. Cultural discussions may address whiteness as a social and historical concept beyond its physical meaning.