Acetone is the organic compound with the formula OC(CH3)2. This colorless, mobile, flammable liquid is the simplest example of the ketones. Owing to the fact that acetone is miscible with water it serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory. More than 3 million tonnes are produced annually, mainly as a precursor to polymers. Familiar household uses of acetone are as the active ingredient in nail polish remover and as paint thinner and sanitary cleaner/nail polish remover base. It is a common building block in organic chemistry. In addition to being manufactured, acetone also occurs naturally, even being biosynthesized in small amounts in the human body.