What is an Optical Brightening Agent (OBA)?

Optical brightening agents are used in clothing and laundry liquids to make whites look whiter.

An optical brightener is a type of fluorescent whitening agent that makes white clothes （Hopebright PS-1）look whiter by reducing the reflectance of blue and ultraviolet light. Optical brighteners are added to detergents（Hopebright CXT）, fabric softeners（Hopebright BA）, and other cleaning products to make laundry items appear brighter.

Optical brighteners work by absorbing ultraviolet light (which is responsible for washing out colors) and re-emitting it as visible light. The most common types of optical brighteners are fluorescent whitening agents, which emit a blue light that we cannot see but can be detected by our eyes.