ABSTRACT
Optical brighteners or also fluorescent whitening agents (FWA) compensate for the yellow tint of fibers by adding blue fluorescence to the light reflected by the fabric. Thus in contrast to bluing agents, FWAs do not only reduce the yellow appearance but also increase the brightness of a fabric. Fluorescent whitening agents have become part of laundry detergent formulations because, first, they enhance the appearance of fabrics by exhausting during laundry processes and, second, they improve the appearance of the detergent powder itself. Fluorescent whitening agents have been successfully used for many decades not only in laundry detergents but also in other laundry products such as bleaches, rinse-conditioners, or whiteness boosters.
