On April 21, 2010, the EPA announced that it would seek public comment on data available for evaluating emissions and potential exposure to lead in gas used in piston-engine aircraft. As the EPA stated:
Emissions of lead from piston-engine aircraft using leaded avgas comprise approximately half of the national inventory of lead emitted to air. EPA estimates that approximately 14.6 billion gallons of leaded avgas were consumed between 1970 and 2007, emitting approximately 34,000 tons of lead.
The EPA will publish an Advanced Notice of Proposed Rulemaking in the Federal Register which describes the data that are currently available and being collected that would help evaluate health impacts from piston-engine aircraft emissions. That will start the 60-day public comment period.
The ANPR is one of the steps EPA has taken in response to a petition that Friends of the Earth filed on October 3, 2006 requesting that the Administrator find that aircraft lead emissions cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare, and that EPA regulate those emissions. The EPA had previously issued a Notice requesting public comment on the Petition in November, 2007, ended up not taking any action.
The Aircraft Owners and Pilots Association (AOPA) has long argued that lead is a necessary component of 100 octane leaded aviation gasoline. For example, two years ago, in response to the Friends of Earth petition, AOPA commented that:
Currently, there is no simple alternative for 100LL avgas. Any change in the current fuel standard will have a direct impact on the safety of flight and therefore must be fully tested and FAA approved before any operational changes occur.
Thus, it is highly likely that EPA’s new push to get the lead out will be met with some resistance again from AOPA.