Inorganic salts or organic esters of arsenious acid.
https://reptox.cnesst.gouv.qc.ca/pages/fiche-complete.aspx?no_produit=52928&nom=Arsenite+de+sodium Canada toxicological data sheet arsenite arsenites sodium
--- https://reptox.cnesst.gouv.qc.ca/pages/fiche-complete.aspx?no_produit=866954&nom=Acétoarsenite+de+cuivre Canada French arsenites copper Paris green toxicological data sheet