Our main barrier spray chemical is a synthetic form of pyrethrum called a pyrethroid. We spray this chemical on shrubs, low lying trees, your foundation, mulch beds, etc. All chemicals we use are EPA approved. Widely used in shampoos, outdoor clothing and protection for pets, Permethrin, our most widely used, is a synthetic insecticide with a long history of safety. A risk/benefit balancing analysis conducted by the EPA saw the benefits of permethrin dramatically outweighing the risks. In a comparative test with DEET, when put directly on the skin, typically less than 1% of active Permethrin ingredient is absorbed into the body; DEET can be absorbed at over 20 times that rate.