The report gives results of an evaluation of Orimulsioni, a bitumen-in-water emulsion produced in Venezuela, to provide a better understanding of the potential environmental impacts associated with its use as a fuel. Pilot-scale tests were conducted at EPA's Environmental Research Center in Research Triangle Park in North Carolina, to provide data on emissions of air pollutants from the combustion of Orimulsion 100 (the original formulation), Orimulsion 400 (a new formulation introduced in 1998), and No. 6 (residual) fuel oil, commonly used in the U.S. These results, and those of full-scale tests reported in the technical literature, were evaluated to determine the potential air pollutant emissions and the ability of commercially available pollution control technologies to adequately reduce those emissions. Results indicate that carbon monoxide, nitrogen oxide, and particulate matter (PM) emissions are likely to be nearly the same as those from No. 6 fuel oil.