The long, slow process to find an alternative to leaded aviation fuel took a step forward in July when the FAA said it will start to evaluate nine possible replacement fuels from five producers. Avgas is the only transportation fuel in the U.S. that still contains added lead, a substance banned from most fuels due to its toxicity. The FAA has set a goal to find a new, unleaded aviation fuel by 2018. This summer, the FAA will analyze the candidate fuels in terms of their impact on the fleet of 167,000 lead-fuel-burning GA aircraft, the production and distribution infrastructure, their environmental impact, toxicology, and cost. By September 1, the FAA will select several of the fuels for further testing. The nine proposals now under evaluation were received from Afton Chemical Company, Avgas LLC, Shell, Swift Fuels, and a consortium of BP, Total, and Hjelmco.