Control of Emissions of Hazardous Air Pollutants From Mobile Sources: Default Baseline Revision

This action revises the mobile source air toxics (MSAT) rule's default baseline values for reformulated gasoline and conventional gasoline to reflect the national average toxics performance of gasoline during 1998-2000. EPA's MSAT rule, Control of Emissions of Hazardous Air Pollutants From Mobile Sources (66 FR 17230, March 29, 2001), requires that the annual average toxic performance of gasoline must be at least as clean as the average performance of the gasoline produced or imported during the period 1998-2000 (known as the "baseline period"). The baseline performance is determined separately for each refinery and importer, and the rule established default toxics baseline values for refineries and importers that could not develop individual toxics baselines. The default toxics baseline values are based on the national average performance of gasoline during the baseline period. However, at the time of the final rule, gasoline toxics performance data were not yet available for the year 2000. Therefore, the final rule included regulations directing the EPA to revise the default toxics baseline values in the rule to reflect the entire 1998-2000 baseline period once the appropriate data became available. With this action, EPA is revising the default toxics baseline values for refineries and importers to reflect the national average toxics performance of gasoline during 1998-2000.