Oxybenzone or benzophenone-3 or BP-3 (trade names Milestab 9, Eusolex 4360, Escalol 567, KAHSCREEN BZ-3) is an organic compound belonging to the class of aromatic ketones known as benzophenones.

It is widely used in sunscreen formulations, plastics, toys, furniture finishes, and other products to limit UV degradation.

The use of oxybenzone as sunscreen ingredient is currently under scrutiny by the scientific community due to controversies about the molecule's environmental impact and safety profile (see section below).

[13] This substance can leach from food packaging, and is widely used as photo-initiators to activate a chemical that dries ink faster.

[14] Despite its photoprotective qualities, much controversy surrounds oxybenzone because of possible negative hormonal and photoallergenic effects, leading many countries to regulate use in sunscreen products.

[16] Some brands market their sunscreens as "oxybenzone free"[17] due to the generally negative perception of benzophenones by both the consuming public and scientific researchers.

[26] When applied topically, UV filters, such as oxybenzone, are absorbed through the skin, metabolized, and excreted primarily through the urine.

[27] The method of biotransformation, the process by which a foreign compound is chemically transformed to form a metabolite, was determined by Okereke and colleagues through oral and dermal administration of oxybenzone to rats.

The scientists analyzed blood, urine, feces, and tissue samples and found three metabolites: 2,4-dihydroxybenzophenone (DHB), 2,2-dihydroxy-4-methoxybenzophenone (DHMB) and 2,3,4-trihydroxybenzophenone (THB).

[52] The European Food Safety Authority categorises All the benzophenones, such as oxybenzone, as persistent, bio-accumulative, toxic, and a possible human carcinogen and endocrine disruptor.

[13] Thailand has prohibited sunscreens containing chemicals harmful to corals, including oxybenzone, in all its marine national parks.

This decision was driven by evidence highlighting the detrimental effects of certain sunscreen ingredients on coral larvae, reproduction, and inducing reef bleaching.

[63] However, this legislation was superseded by the Florida State Legislature by Senate Bill 172,[64] which prohibits local governments from regulating over-the-counter proprietary drugs and cosmetics (such as sunscreen containing oxybenzone and octinoxate).