Title: Roxarsone
CAS Registry Number: 121-19-7
CAS Name: 4-Hydroxy-3-nitrophenylarsonic acid
Additional Names: 4-hydroxy-3-nitrobenzenearsonic acid; 3-nitro-4-hydroxyphenylarsonic acid; 2-nitro-1-hydroxybenzene-4-arsonic acid; nitrophenolarsonic acid
Manufacturers' Codes: NSC-2101
Trademarks: Ren-o-sal (Salsbury)
Molecular Formula: C6H6AsNO6
Molecular Weight: 263.04
Percent Composition: C 27.40%, H 2.30%, As 28.48%, N 5.32%, O 36.49%
Literature References: Prepd by treating sodium p-hydroxyphenylarsonate with a mixture of nitric and sulfuric acids at 0°: Benda, Bertheim, Ber. 44, 3446 (1911); DE 224953 C.A. 5, 156 (1911). Toxicity study: Kerr et al., Toxicol. Appl. Pharmacol. 5, 507 (1963). Review of toxicology and human exposure: Toxicological Profile for Arsenic (PB2000-108021, 2000) 468 pp.
Properties: Tufts of pale-yellow needles or rhombohedral plates from water. Puffs up and deflagrates on heating. Slightly sol in cold water; sol in ~30 parts boiling water; freely sol in methanol, ethanol, acetic acid, acetone, alkalies; sparingly sol in dil mineral acids. Insol in ether, ethyl acetate. Forms mono-, di-, and trisodium salts. LD50 in rats, chickens (mg/kg): 155, 110-123 orally; 66, 34 i.p. (Kerr).
Toxicity data: LD50 in rats, chickens (mg/kg): 155, 110-123 orally; 66, 34 i.p. (Kerr)
Use: Formerly in manuf arsphenamines; as reagent for zirconium.
Therap-Cat-Vet: Control of enteric infections. To improve growth and feed efficiency.
Roxatidine Acetate Roxithromycin Royal Jelly Rubber Rubeanic Acid

Kekulé, skeletal formula of 4-hydroxy-3-nitrobenzenearsonic acid
CAS number 121-19-7 YesY
PubChem 5104
ChemSpider 4925 YesY
EC number 204-453-7
UN number 3465
KEGG D05771 YesY
MeSH Roxarsone
ChEBI CHEBI:35817 YesY
RTECS number CY5250000
Beilstein Reference 1976533
Gmelin Reference 1221211
Jmol-3D images Image 1
Image 2
Molecular formula C
Molar mass 263.0365 g mol-1
Melting point >300 °C
GHS pictograms The skull-and-crossbones pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word DANGER
GHS hazard statements H301, H331, H410
GHS precautionary statements P261, P273, P301+310, P311, P501
EU classification Toxic T Dangerous for the Environment (Nature) N
R-phrases R23/25, R50/53
S-phrases S20/21, S28, S45, S60, S61
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

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.[2] The drug is also approved in the United States for use in pigs.[2] Roxarsone is marketed as 3-Nitro by Zoetis, a publicly traded subsidiary of Pfizer. In 2006, approximately one million kilograms of roxarsone were produced in the U.S.[3]

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.[2] 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.[4] Roxarsone is banned in the European Union.[5]