The image shows how optical brighteners in carpet cleaning compounds and spotters glow under ultraviolet light.
They are used by some carpet cleaning chemical manufacturers who don’t realize (or dont’t care) that their use will permanently cause the carpet to turn yellow. Unfortunately, once a carpet cleaning detergent or spotter that contains an optical brightener has been used to clean a carpet it is nearly impossible to remove; so the yellow color stays. Since these are dyes, there is no cure for this problem.
Optical brighteners are frequently found in carpet shampoos and bonnet cleaning compounds. Carpet manufacturers and the Carpet and Rug Institute (CRI) don’t approve of carpet cleaners containing optical brighteners. Using an optical brightener will void the warranty by most carpet manufacturers. Yet, some manufacturers still use them!
Per the CRI Seal of Approval program Standard for Testing Cleaning Solutions, “Optical brighteners — None are allowed, as they can leave some patches of carpet lighter than the rest. … The presence of optical brighteners in carpet cleaning products has been known to adversely affect long-term appearance.”
Bane-Clene does not manufacture any carpet cleaning detergent or spotter that contain optical brighteners.