Lorsban™ 4E controls insects on contact, through ingestion, and vapour inhalation. Lorsban™ 4E is an organophosphate insecticide, and has a longer residual effect than synthetic pyrethriod insecticides. It is non-systemic in plants, meaning the active ingredient is not taken up by the plant. Lorsban 4E is one of the most-widely used insecticides in the world. The active ingredient in Lorsban™ 4E, clorpyrifos, was first registered in 1965 and has been on the market more than 40 years. More than 3,600 studies and over $100 million has been spent examining the critical aspects of chlorpyrifos products as they relate to health and safety. In terms of human health and safety, no pest control product has been more thoroughly studied.