Piperonyl butoxide and n-octyl bicycloheptene dicarboximide often are added to pyrethrin products to inhibit insects' microsomal enzymes that detoxify pyrethrins.
The tree is of special concern, as it is being harvested at a high rate to obtain safrole, a precursor to the pesticide synergist piperonyl butoxide, the flavorant and fragrance piperonal, and the psychoactive drug MDMA.