Given the extensive non-dietary use of PBO, manufacturers of PBO and marketers of PBO-containing products formed the Non-Dietary Exposure Task Force (NDETF) in 1996 to develop a long-term research program to more fully understand the phenomenon of human exposure to insecticides used in the home. Most of the studies were conducted with formulations of pyrethrins/PBO and synthetic pyrethroids/PBO, and focused on the indoor use of fogger and aerosol products. Carpet and vinyl flooring surfaces were selected because of their different physical and chemical properties, and because they represent a significant percentage of the floor coverings used in homes in North America.