Fuels and Fuel Additives
Feedback within the Gasoline Additive MMT (methylcyclopentadienyl manganese tricarbonyl) Common Information
MMT is actually a gasoline octane enhancer produced by the Afton Chemical Corporation (Afton), previously referred to as the Ethyl Corporation. MMT is allowed in U.S. gasoline at a degree equivalent to 1/32 grams per gallon manganese (gpg Mn).
History: Clean Air Act Section 211(f)(four) Waiver
In its decision on the utilization of MMT inside the U.S., the Agency determined that MMT, extra at 1/32 gpg Mn, will not trigger or contribute to regulated emissions failures of automobiles. Some have expressed concerns that the use of MMT might hurt on-board diagnostic gear (OBD) which screens the overall performance of emissions management units in the car. As of this time, the Agency believes the info collected is inconclusive regarding OBD.
Background: Clean Air Act Section 211(b) Health Results Testing
Manganese can be a neurotoxicant at sufficiently higher coverage amounts, quite possibly creating irreversible neurotoxicity or other adverse well being effects. Even so, ingested manganese is a necessary element from the diet plan at lower amounts. There's a concern the utilization of manganese additives in gasoline could enhance inhaled manganese exposures.
After finishing a 1994 chance analysis on the utilization of MMT in gasoline, EPA was unable, depending on the accessible data, to determine if there is a risk for the public well being from publicity to emissions of MMT gasoline. The Company stated "Although it is not possible depending on the present info to conclude whether specific adverse wellbeing results will be associated with manganese exposures from the vicinity of or exceeding the [estimated safe level over a lifetime of exposure], neither is it possible to conclude that adverse well being effects won't be associated with such exposures." This assessment was primarily based upon the stage of MMT allowed in U.S. gasoline.
More specifically,
Office 2007 Serial, modeling indicates that, as a result of MMT use in unleaded gasoline, certain portions from the population might be exposed to amounts in the same range since the Reference Concentration (RfC or safe degree for a lifetime exposure with an order of magnitude uncertainty). Because the expected coverage is not much higher or much lower than the RfC, a definitive conclusion about danger is impossible to reach. Long-term animal testing and publicity research are needed to more accurately define the chance.
Under Clear Air Act authority to require testing of motor fuels and additives, EPA has required the Afton Corporation to perform testing to help fill information gaps and provide information that potentially would result in a more definitive chance evaluation.
This testing included three well being pharmacokinetic (PK) studies and one emission characterization study. Completed final reports for all of these studies have been submitted to EPA. These final reports may be found within the Federal Docket Management System (FDMS) at www.regulations.gov identified by docket number EPA-HQ-OAR-2004-0074.
In addition to your already completed tests, the manufacturer developed physiologically-based pharmacokinetic (PBPK) models for manganese which were derived from information generated from the completed testing. Afton completed those PBPK models in 2010.
With funding from Afton, Research Triangle Institute (RTI) has also completed a study of manganese exposures in Toronto, Canada where MMT has been used. The Company is also evaluating this study to find out what impact it might have on any analysis of publicity to manganese associated with use of the additive.
The Agency will study the results of all the Afton studies and other obtainable data. The Agency may possibly then be able to refine its chance analysis and/or could ask for further testing.
Contact: Mr. Joe Sopata (sopata.joe@epa.gov), telephone: 202-343-9034
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