Salt marsh ecosystems are sensitive habitats that may be susceptible to oil and oil spill mitigation chemicals during clean up. This research project assessed the toxicity of three shoreline cleaners (SLC) in laboratory and mesocosm exposures, determined petroleum hydrocarbon distributions in water and sediment, and evaluated efficacy of each SLC in oil (Louisiana Sweet Crude; LSC) removal from artificial substrates. The three SLC selected were PES-51, CytoSol, and Accell Clean SWA. In the mesocosm experiment, the greatest animal mortality (fish, snails, clams, amphipods and polychaetes) occurred in the Oil+Accell Clean treatment. Clam growth was reduced in the Oil+Accell Clean and CytoSol treatments. There was an increase in bacterial densities and a decrease in dissolved oxygen content in the Oil+Accell Clean treatment. Water column hydrocarbon concentrations were greatest in the Oil+Accell and Oil+CytoSol treatments after 7 d but decreased rapidly in all treatments after 30 d. In laboratory testing, grass shrimp were most sensitive to Accell Clean, followed by PES-51, then CytoSol. Effects on larval growth and development were observed. Accell Clean prepared as a chemically enhanced water accommodated fraction (CEWAF) with LSC oil was observed to act as a dispersant, mixing oil into solution and yielding greater concentrations of soluble hydrocarbons than PES-51 prepared as a CEWAF. Results of the oil-removal efficiency study with shoreline cleaners indicate that PES-51 and CytoSol were more effective at removing oil from the artificial substrates than Accell Clean. This new information on SLC product toxicity and chemical interactions with oil will allow managers to make more informed oil spill mitigation decisions.