What is "roxarsone"

n. The compound ''4-hydroxy-3-nitrobenzenearsonic acid'' once used as an additive in chicken feed

Roxarsone is an organoarsenic compound that is widely used in poultry production as a feed additive to increase weight gain and improve feed efficiency, and as a coccidiostat. The drug is also approved in the United States for use in pigs. Roxarsone is marketed as 3-Nitro by Zoetis, a former subsidiary of Pfizer now a publicly traded company. In 2006, approximately one million kilograms of roxarsone were produced in the U.S.

Roxarsone is one of four arsenical animal drugs approved by the U.S. Food and Drug Administration (FDA) for use in poultry and/or swine, along with nitarsone, arsanilic acid, and carbarsone. In September 2013, the FDA announced that Zoetis and Fleming Laboratories would voluntarily withdraw current roxarsone, arsanilic acid, and carbarsone approvals, leaving only nitarsone approvals in place. In 2015 FDA withdraw the approval of using nitarsone in animal feeds. The ban will came into effect at the end of 2015. Roxarsone is banned in the European Union.