Main Page | See live article | Alphabetical index Benzone, formally phenylbutazone, is the ketone of benzoic acid (diphenyl ketone). It is a crystalline substance. Structural name: 4-Butyl-1,2-diphenyl-3,5-pyrazolidinedione Chemical formula: C19H20N2O2 It is used as a Non-Steroidal Anti-Inflammatory Drug (NSAID) for the treatment of chronic pain, including the symptoms of arthritis. Its use is limited by its side-effect of suppressing the production of white blood cells by bone marrow. The International Agency for Research on Cancer (IARC) places it in Group 3, i.e., "not classifiable as to its carcinogenicity to humans". Benzone is also sometimes used to refer to the active ingredients in sunscreen that end in "benzone" (such as oxybenzone, dioxybenzone, avobenzone, and sulisobenzone), which are benzophenone derivatives. These chemicals offer protection against UVB. External Links IARC monograph on carcinogenicity of phenylbutazone This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.