Diethylamino hydroxybenzoyl hexyl benzoate (DHHB) is an organic UV filter with high absorption in the UV-A range that minimizes the overexposure of human skin to ultraviolet radiation that may lead to acute and chronic photodamage. In in vitro studies, DHHB was not shown to be mutagenic, clastogenic, or phototoxic. DHHB was approved in Europe in 2005, is also marketed in the U.S., South America, Mexico, Japan and Taiwan, and is used in concentrations up to 10% in sunscreen products, either alone or in combination with other UV absorbers. Only a minor amount of diethylamino hydroxybenzoyl hexyl benzoate will undergo percutaneous absorption and most will remain in the upper layers of the skin. Fluorescence spectroscopy showed that DHHB and avobenzone (another chemical sunscreen ingredient) interact by a static quenching mechanism and DHHB did not affect the avobenzone excited state lifetime.