Lambda-cyhalothrin (λ-cyhalothrin), a mixture of isomers of cyhalothrin belongs to a class of insecticides known as synthetic pyrethroids. Synthetic pyrethroids are often preferred to the real thing as an active ingredient because they offer the added bonus of remaining effective for longer period. λ-cyhalothrin was the most commonly used pyrethroid insecticide for vegetable farming in Benin. Experiments have shown that λ-cyhalothrin residues in lettuce and cabbage from farms and markets in Parakou and Cotonou were relatively safe for consumption.