Roxarsone is an

organoarsenic compound Organoarsenic chemistry is the chemistry of Chemical compound, compounds containing a chemical bond between arsenic and carbon. A few organoarsenic compounds, also called "organoarsenicals," are produced industrially with uses as insecticides, herb ...

that has been used in poultry production as a feed additive to increase weight gain and improve feed efficiency, and as a coccidiostat. As of June 2011, it was approved for chicken feed in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

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, and 12 other countries. The drug was also approved in the United States and elsewhere for use in

pigs The pig (''Sus domesticus''), also called swine (: swine) or hog, is an omnivorous, domesticated, even-toed, hoofed mammal. It is named the domestic pig when distinguishing it from other members of the genus '' Sus''. Some authorities cons ...

. Its use in the United States was voluntarily ended by the manufacturers in June 2011 and has been illegal since 2013. Its use was immediately suspended in Malaysia. It was banned in Canada in August 2011. In Australia, its use in chicken feed was discontinued in 2012. Roxarsone has been banned in the European Union since 1999.

Production and applications

Roxarsone is a derivative of phenylarsonic acid (C₆H₅As(O)(OH)₂). It was first reported in a 1923 British patent that described the

nitration In organic chemistry, nitration is a general class of chemical processes for the introduction of a nitro group () into an organic compound. The term also is applied incorrectly to the different process of forming nitrate esters () between Alcohol ...

and diazotization of arsanilic acid. When blended with calcite powder, it is used in poultry feed premixes in some parts of the world. Where available, it can be purchased in 5%, 20% and 50% concentrations. Roxarsone was marketed as 3-Nitro by Zoetis, a former subsidiary of

Pfizer Pfizer Inc. ( ) is an American Multinational corporation, multinational Pharmaceutical industry, pharmaceutical and biotechnology corporation headquartered at The Spiral (New York City), The Spiral in Manhattan, New York City. Founded in 184 ...

now a publicly traded company. In 2006, approximately one million kilograms of roxarsone were produced in the U.S.

Marketing approval in the United States

Roxarsone is one of four

arsenical Arsenicals are chemical compounds that contain arsenic. In a military context, the term arsenical refers to toxic arsenic compounds that are used as chemical warfare agents. This includes blister agents, blood agents and vomiting agents. Historica ...

animal drugs that had been approved by the U.S. Food and Drug Administration (FDA) for use in poultry and 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, the FDA withdrew the approval of using nitarsone in animal feeds. The ban came into effect at the end of 2015.

Controversy

Roxarsone has attracted attention as a source of

arsenic Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

contamination of poultry and other foods. In June 2011, the manufacturers suspended sales of roxarsone in the U.S. and Canada in response to a study by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA). The FDA found that roxarsone use was associated with elevated levels of inorganic arsenic in chicken livers. An FDA press release stated that the findings raised "concerns of a very low but completely avoidable exposure to a carcinogen." A 2013 market basket study conducted in the United States linked the use of roxarsone and other arsenical feed additives to increased levels of inorganic arsenic in chicken breast meat, albeit at concentrations well below danger levels set in federal safety standards. Breast meat from chickens exposed to arsenical feed additives contained inorganic arsenic at the level of about two parts per billion. Organic chickens not exposed to arsenical feed additives contained about half a part per billion. Federal standards permitted concentrations of 500 parts per billion of total arsenic. The study was performed on chickens raised prior to the voluntary withdrawal of Roxarsone from the market by its manufacturer in June 2011.

References

External links

No Arsenic In Pardoned Turkeys, But It Might Be In Yours
at NPR Arsonic acids Antiprotozoal agents Veterinary drugs Food safety Medicated feed Nitrophenol derivatives

Production and applications

Marketing approval in the United States

Controversy

References

Further reading

External links