This paper reviews environmental concerns relating to the distribution, handling, and end use of synfuel products likely to enter the marketplace by the year 2000, and assigns priority rankings to the products based on environmental concerns to aid EPA to focus its regulatory and research activities. Major products and by-products from oil shale, coal liquefaction, and coal gasification technologies are considered. Results indicate that: (1) significant quantities of synfuel products are expected to enter the marketplace during the next 20 years; (2) large-scale transportation, distribution, and end use of certain synfuel products can present significant threats to the environment and the public health; (3) based on gross characteristics, synfuel products appear to be similar to petroleum products, but detailed characterization data are not available with which to judge their relative safety; and (4) synfuel test and evaluation programs currently underway or planned provide excellent opportunities for collecting some of the required environmental data. Three likely scenarios for shale- and coal-based synfuel plant buildup are projected. The type and quantity of synfuel products and by-products likely to enter the market are identified and their regional market penetration is estimated. The environmental analysis consists of a review of available data on the physical, chemical, and health effects characteristics of synfuel products and environmental significance of their characteristics.