Endosulfan I is an organochlorine insecticide and a stereoisomer of endosulfan II . It is active against a variety of insects, including bollworms (LD50 = 0.63 mg/g). Endosulfan I binds to GABA receptors in rat brain membranes with an IC50 value of 30 nM and is toxic to rats (LD50 = 18 mg/kg).

Endosulfan II, an organochlorine insecticide and a stereoisomer of Endosulfan I, effectively targets various insects such as bollworms and tobacco budworms, with lethal doses (LD50s) of 4.14 and 4.95 mg/g, respectively. It interacts with GABA receptors in rat brain membranes, demonstrating an inhibition concentration (IC50) of 60 nM. Notably, Endosulfan II exhibits lower toxicity in rats compared to Endosulfan I, with LD50 values of 240 and 18 mg/kg, respectively.