"The devastating health effects of lead are well documented," Waxman wrote to FAA Acting Administrator Michael Huerta on Tuesday. "Lead is a potent neurotoxin that has especially debilitating effects on children, damaging the brain and nervous system and impairing development."

He said these effects are made worse by the close proximity of some general aviation airports to residential areas.

However, Waxman said the FAA's current plans are to address leaded general aviation fuel starting with testing an unleaded replacement fuel by 2018. But he said there would be no requirement to use that fuel until at least 11 years after that.

"This extended time-frame is simply too long, given the certain and serious harms to human health from lead exposure and the availability of alternatives to leaded fuels," he wrote.

Waxman said unleaded fuels are already available and could be used in the United States, and said some of these fuels are already being used in Europe. While he acknowledged that some barriers exist, including supply, technology and pilot education, they are not insurmountable,

"It is essential for the FAA to develop and implement, in the near term, measures to facilitate the use of currently available unleaded fuel in general aviation," he wrote. "I urge you to engage airports, particularly those in densely populated areas, to resolve these obstacles and promote the broader use of available unleaded alternatives for piston aircraft."