Agent Name


Alternative Name

3-Nitro-4-hydroxyphenylarsonic acid

CAS Number




Major Category



3-Nitro-4-hydroxyphenylarsonic acid; 2-Nitro-1-hydroxybenzene-4-arsonic acid; 3-Nitro; 3-Nitro-10; 3-Nitro-20; 3-Nitro-4-hydroxybenzenearsonic acid; 3-Nitro-50; 3-Nitro-80; 3N4HPA; 4-Hydroxy-3-nitrobenzenearsonic acid; 4-Hydroxy-3-nitrobenzolarsonsaeure; 4-Hydroxy-3-nitrophenylarsonic acid; A 19603; Aklomix-3; Arsonic acid, (4-hydroxy-3-nitrophenyl)-; Benzenearsonic acid, 4-hydroxy-3-nitro-; Kyselina 4-hydroxy-3-nitrofenylarsonova [Czech]; NIH 1529; Nitro acid 100 per cent; Nitrophenolarsonic acid; Ren O-sal; Ren-O-sal; Ristat; Roxarson [INN-Spanish]; Roxarsonum [INN-Latin]; [ChemIDplus] UN3465


Arsenic Compounds, Organic


Pale yellow solid; [Merck Index] Fine yellow crystals; [MSDSonline]


Used as an antimicrobial agent (growth promoter) for poultry and swine, a reagent for zirconium, formerly in the manufacture of arsphenamines, and as a veterinary medicine for control of enteric infections; [HSDB]


May cause arsenic poisoning; [CAMEO] "Almost nothing is known regarding health effects of organic arsenic compounds in humans. Studies in animals show that some simple organic arsenic compounds are less toxic than inorganic forms. Ingestion of methyl and dimethyl compounds can cause diarrhea and damage to the kidneys." [ATSDR ToxProfiles] Marginally increased incidence of pancreatic adenomas in 2-year feeding studies of rats; Repeated oral doses (0.87-5.8 mg/kg/day for 1 month) to pigs causes neurotoxicity with axonal degeneration and partial paralysis. Causes kidney injury in animals in acute toxicity testing; Oral LD50 (rat) = 81 mg/kg; [HSDB] In order of decreasing toxicity are inorganic trivalent, organic trivalent, inorganic pentavalent, and organic pentavalent compounds. [Sullivan, p. 858] Arsenic and arsenic compounds are carcinogenic in humans (not necessarily to all individuals chemicals within the group). [IARC] May cause irritation; Targets pancreas, kidneys, and nerves; Effects in high-dose animal studies include diffuse hepatitis (hepatocellular necrosis) and kidney damage; [MSDSonline] See "Arsanilic acid."

Reference Link

Abstract for TR-345 - Roxarsone (CASRN 121-19-7) - National Toxicology Program

Exposure Assessment

0.5 mg/m3, as As

Vapor Pressure

2.74E-10 mm Hg

Explanatory Notes

The Guide in the Emergency Response Guidebook is for "Organoarsenic compound, solid, n.o.s."

Adverse Effects

Hepatotoxin, Secondary

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

Search ChemIDplus

Related Information in HazMap

Industrial Processes with risk of exposure: