Isomalathion is an impurity found in some batches of malathion, depending on its method of preparation. It is significantly more toxic to humans than malathion.

CAS：3344-12-5
中文别名：异马拉硫磷;
英文别名：isomalathion;s-methylmalathion;O-S-Dimethylphosphorodithioat von Diethylmercaptosuccinat;succinicacid,mercapto-,diethylester,s-esterwitho,s-dimethylphosphorodit;8063hc;
分子式：C10H19O6PS2
分子量：330.358
精确质量：330.036
Psa：139.31
Logp：2.722

密度：1.273g/cm3
沸点：413.6ºC at 760mmHg
闪点：203.9ºC
折射率：1.501

危险类别码：R22; R50/53
海关编码：2931900090
危险品运输编码：UN 1208 3/PG 2
危险品标志：Xn; N