Office of Transportation                           EPA420-F-05-034
Environmental Protection and Air Quality                                 September 2005
Agency           	
               Regulatory
               Announcement
               Final Rulemaking Revising MSAT
               Default Baseline Values
               The U. S. Environmental Protection Agency (EPA) is issuing a final
               rulemaking which revises the Mobile Source Air Toxics (MSAT) Rule
               default baseline values. This rulemaking also corrects an error in the
               MSAT reformulated gasoline (RFG) default baseline value published in
               the original rule.
               Background
               The final MSAT rule, published March 29, 2001 (as Control of Emis-
               sions of Hazardous Air Pollutants From Mobile Sources), requires that
               the annual average toxics performance level of gasoline produced or
               imported beginning in 2002 must be at least as clean as the average
               performance level of the gasoline produced or imported during the
               baseline period 1998-2000. Toxics performance is determined separately
               for each refinery and importer. Toxics performance is also determined
               separately for RFG and conventional gasoline.

               The MSAT default baseline applies to the gasoline of those parties who
               cannot establish a unique individual MSAT baseline under the MSAT
               rules. Such parties may not have existed during the MSAT baseline
               period, or did not have sufficient gasoline production or import activity
               during that period. The default MSAT baseline is an estimate of the
               nationwide annual average toxics performance level of gasoline. Toxics

-------
performance data from calendar year 2000
was not yet available when the 2001
MSAT rule was promulgated. In that rule,
we committed to revise the default MSAT
baseline values once the 2000 data became
available. This rulemaking fulfills that
commitment.

The proposed rule for this rulemaking was
published on January 4, 2005. We had
proposed that the revised values would be
effective with the annual compliance
period beginning January 1, 2005. Consid-
ering the timing of the proposed and final
rules,  and comments from refining indus-
try representatives, we are instead finaliz-
ing an effective date of January 1, 2006.
Industry representatives commented that a
compliance period beginning the  year
following promulgation of the revised
values would provide  sufficient lead time
to prepare for the new requirements, as
long as promulgation occurred by Septem-
ber 30.

This rulemaking also corrects an  error in
the original rule affecting the RFG default
baseline value. The corrected value is
effective for the 2002-2005 compliance
periods.
Health      Environmental
Benefits
The final MSAT rule set gasoline toxic
emission performance standards to ensure
that refiners and importers maintain their
average 1998-2000 gasoline toxic emis-
sion performance levels. This rule updat-
ing the default MSAT baseline values does
not change the environmental analyses
discussed in the final MSAT rule.
Effect on Industry
The revised conventional gasoline default
baseline value is less stringent than the
current conventional gasoline value. The
revised RFG default baseline value is
slightly more stringent than the current
RFG value. Nonetheless, EPA expects this
rule to have minimal economic conse-
quences.
For More Information
Information on the rulemaking is available
from the EPA Air Docket (202-566-1742);
please refer to Docket No. OAR-2002-
0042. In addition, you can access the final
rule and related documents on EPAs
Office of Transportation and Air Quality
(OTAQ) Web site at:

    www.epa.gov/otaq/toxics.htm

For further information on this final rule,
please contact Christine Brunner at:

U.S. Environmental Protection Agency
National Vehicle and Fuel Emissions
Laboratory
2000 Traverwood Drive
Ann Arbor, MI 48105
(734)214-4287
    E-mail: brunner.christine@epa.gov

-------