The classes of primary chemical products naturally produced by the combustion of forest fuels are: carbon dioxide, water, carbon monoxide, particulate matter, methane and non-methane hydrocarbons, polynuclear aromatic hydrocarbons, nitrogen and sulfur oxides, aldehydes, free radicals, and inorganic elements. Secondary chemical products produced by reactions in smoke plumes or volatilized exotic chemicals include ozone and pesticides. With the extensive use of herbicides for site preparation and release in some forest ecosystems and insecticides for insect control in others, public concern has increased about the fate of pesticides in fires. Studies conducted on herbicides and insecticides indicate that hot fires (>500ºC) thermally degrade most pesticides. Smoldering fires (<500ºC) have the potential to volatilize significant amounts of some pesticides. Exposure analyses indicate that, even under conditions of smoldering fires, no significant human health risks occur from pesticides incorporated into or on forest fuels. © 2000, Tall Timbers Research, Inc. Abstract reproduced by permission.