ANNAPOLIS, Md. – Maryland Gov. Martin O’Malley signed a bill into law that will ban roxarsone, an additive containing organic arsenic, from chicken feed starting in 2013. Maryland is the first state to have such a law on its books.

Roxarsone is an organic arsenic-based drug that was manufactured by Alpharma LLC, a subsidiary of Pfizer Inc. Used in combination with other drugs, the chemical helps birds fight parasitic disease such as coccidiosis which infects the intestinal tracts in poultry and can lead to death. Roxarsone was also approved for weight gain, improved pigmentation in chickens and feed efficiency, according to the Food and Drug Administration.

In April, the National Chicken Council (NCC) defended the wholesomeness of chickens produced in the US in light of the roxarsone issue.

“Chickens in the US produced for meat are not given ‘arsenic’ as an additive in chicken feed, or any of the other compounds mentioned in this study,” the NCC said in a statement. “Some flocks used to be given feed that contained a product called roxarsone, which is a molecule that includes organic arsenic – not the inorganic, trivalent form that is considered a poison.

“This product was removed from the market last year, it is no longer manufactured and it is no longer used in raising chickens in the US,” NCC said.