Optical Brightener

Do you remember “bluing” that your mom or grandmother used to add to the rinse water when doing laundry? I’m showing my age aren’t I? Bluing made whites-whiter, and all your other clothes looked brighter and cleaner too. What the bluing did was counter-act a dingy, yellow appearance fabrics took on. Although bluing is still available, a fluorescent dye or "whitening" agent called optical brightener is now used in nearly all laundry detergents and fabric softeners. Optical brighteners reflect the ultraviolet portion of the light spectrum as blue-white light. This is the stuff that made your shirt glow at the roller rink. Because optical brighteners do such a great job in our laundry, it was very common to find it added to carpet cleaning detergents and spot and stain removers used on carpet. 
 
Optical brightener while useful with laundry, is often associated with permanent yellowing of carpet. Cleaning agents with optical brightener in them may affect the dyes causing a gradual loss of color over an extended period of time. As optical brighteners degrade, they turn yellow and cannot be removed, leaving your carpet with a yellowed appearance.

Spot removers with optical brightener in them can, at times, leave a spot looking purple in color under normal day light, or sometimes leave a lighter color halo around the spot that cannot be removed. Note the size and shape of these spots that have optical brightener in them viewed under ultraviolet light.

Compared to these photos of animal urine viewed under ultraviolet light

Detergents with optical brightener in them should never be used on your carpet.  I cannot think of one carpet manufacturer that allows detergents or spot removers with optical brightener in them to be used on their carpet. Some manufacturers will void your warranty if detergents with optical brightener in them are ever used on your carpet.
 
It amazes me that after all these years, and with all the fabulous carpet cleaning detergents and spot removers readily available from reputable formulators, optical brightener is still found in some of them.
 
A simple test I use to determine if carpet cleaning detergents or spot removers have optical brightener in them is to pour some of it on a white coffee filter, then rinse it under running water. I then take an ultraviolet light and direct the light on it. If it fluoresces blue-white in color, it has optical brightener in it, and should never be used on carpet.
 
One more tidbit, I often inspect carpet for seam issues, such as fraying and raveling. Many adhesive manufacturers of seam sealer adhesives add optical brightener to them so inspectors like me can direct ultraviolet light at the seam edges to see if the edges of the carpet fluoresces a blue-white color.

This allows me to see if the seam sealer was applied, and if so, was it applied properly.
 
While optical brighteners may make your ‘brights brighter and whites whiter’, stay away from them when it comes to carpet. Usually just water or water and a non-lotion dish detergent or hydrogen peroxide will get out most spots. Need more help? Call us!