Bifenthrin (BF)

Bifenthrin is a pyrethroid insecticide used primarily against the red imported fire ant by influencing its nerve system. It has a high toxicity to aquatic organisms. There are two types of pyrethroids, the ones with α-cyanogroup and the ones without an α-cyanogroup. The neurotoxicity of bifenthrin is based on the affinity with voltage-gated sodium channels (both in insects as in mammals). The pyrethroids with an α-cyano-group block the closing of the sodium-channel permanently, causing the membrane to be permanently depolarized. The resting potential will not be restored, and no further action potential can be generated. The pyrethroids without an α-cyanogroup, to which bifenthrin belongs, are only able to bind to the sodium-channel transiently. This will result in so-called after potentials and eventual continuous firing of axons. The resting potential is not affected by these pyrethroids.