This article provides environmental information on acrolein including environmental fate, potential for human exposure, analytical methods, and a listing of regulations and advisories. Acrolein may be released to the environment in emissions and effluents from its manufacturing and use facilities, in emissions from combustion processes (including cigarette smoking and combustion of petrochemical fuels), from direct application to water and waste water as a slimicide and aquatic herbicide, as a photooxidation product of various hydrocarbon pollutants found in air (including propylene and 1,3-butadiene), and from land disposal of some organic waste materials. Acrolein is a reactive compound and is unstable in the environment. The general population may be exposed to acrolein through inhalation of contaminated air and through ingestion of certain foods. Important sources of acrolein exposure are via inhalation of tobacco smoke and environmental tobacco smoke and via the overheating of fats contained in all living matter. There is potential for exposure to acrolein in many occupational settings as the result of its varied uses and its formation during the combustion and pyrolysis of materials such as wood, petrochemical fuels, and plastics.