Adipic acid is an alpha,omega-dicarboxylic acid that is the 1,4-dicarboxy derivative of butane. It has a role as a food acidity regulator and a human xenobiotic metabolite. It is a conjugate acid of an adipate(1-). Adipic acid or hexanedioic acid is the organic compound with the formula (CH₂)₄(COOH)₂. From an industrial perspective, it is the most important dicarboxylic acid. This white crystalline powder is used mainly for the production of nylon. It is also used in some calcium carbonate antacids to make them tart.