Malaoxon (Liromat, Malation oxon, Malthon oxon) is a chemical compound with the formula C10H19O7PS. More specifically, it is a phosphorothioate. It is a breakdown product of, and more toxic than, malathion. Malaoxon (Liromat, Malation oxon, Malthon oxon) is a chemical compound with the formula C10H19O7PS. More specifically, it is a phosphorothioate. It is a breakdown product of, and more toxic than, malathion.