organoarsenical

Organoarsenicals are a class of organometallic compounds that contain carbon–arsenic bonds. They include aryl and alkyl derivatives in which arsenic is in trivalent (As(III)) or pentavalent (As(V)) oxidation state. The presence of organic substituents differentiates organoarsenicals from inorganic arsenic species and influences their chemical behavior, biological uptake, and environmental fate.

Many organoarsenicals have been prepared for agricultural and medicinal use. Common examples include arsanilic acid (p-aminophenyl arsonic acid) and roxarsone (3-nitro-4-hydroxyphenyl arsonic acid). These compounds have been employed as feed additives to promote growth in poultry and swine, though their use has faced regulatory scrutiny due to the risk of arsenic residues in edible tissues.

Organoarsenicals also appear in medical history. Arsenic-containing drugs such as Salvarsan (arsphenamine) and melarsoprol have been used to treat parasitic diseases; these agents are potent but have notable toxicity. Today, many organoarsenicals are restricted or phased out in clinical and agricultural contexts, with ongoing assessment of safety and environmental impact.

Environmental and health concerns center on arsenic toxicity. Organometallic arsenic compounds can release inorganic arsenic or persist in tissues and soils, presenting risks to human health and ecosystems. Regulatory agencies in many countries have restricted or banned certain organoarsenicals and require monitoring of arsenic levels in food, water, and waste streams.