UV Brighteners: Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs) or fluorescent whitening agents (FWAs) are chemical compounds that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the electromagnetic spectrum, and re-emit light in the blue region (typically 420-470 nm).
These additives are often used to enhance the appearance of color of fabric and paper, causing a “whitening” effect, making materials look less yellow by increasing the overall amount of blue light reflected.
An optical brightener, found in some laundry detergents, makes fabrics appear brighter. It coats clothing in the washing machine and sticks to fabric even after rinsing. Optical brighteners can cause skin irritation. Some, like triazine-stilbenes, do not break down easily and can accumulate in the environment, where they can be toxic to aquatic life. These chemicals are not allowed in some third-party certification standards for green cleaners. Avoid them when you can. (EWG)