The very first things of many detergents is to allow you clothes especially the light colour ones a brightness and whiteness that makes it look brand new. Television commercials of detergents are usually replete with references to this whiteness or brightness, which makes it a huge selling point among consumers and buyers. How does a detergent then, do this – as clothes naturally suffer from wear and tear eventually? The answer lies in optical brighteners and how optical brighteners work.
Optical brighteners are chemicals that serve to make a piece of fabric appear or look to be cleaner (or whiter in the case of white fabrics). They also have characteristics that help lessen the natural yellowing of fabric over time. These whitening agents, also called fluorescent bleaches, brightening agents, and optical whiteners are descendants of a sort from the olden day “bluing agents” which served to remove the yellow tinge in washed clothes, thereby making a white cloth appear to be visibly whiter.
How optical brighteners work is based on a different principle. Optical brighteners are essentially like an ultraviolet dye you apply on clothes. Clothes treated with detergents with optical brighteners absorb ultraviolet light that hits it, and projects it back to your eyes as blue light, which makes the fabric look brighter or whiter to you. The key word here is “look”, because while your clothes indeed appear to be visibly whiter, they are no less clean or in no way cleaner than detergents without optical brighteners.
There are no concrete studies that show optical brighteners having any bad effects on humans, except on those with sensitive skin. Often the itchiness, rashes, and irritation that some individuals with sensitive skin suffer are from how optical brighteners work, but are limited to the irritation, and have no proven lasting health hazards.