mmt® is a safe and environmentally friendly fuel additive based on the extensive testing that has been carried out over the years. The chronology below charts some of the key events in the history of mmt®.
General timeline
Regional timelines:
General
1958
mmt® is commercialized.
1960’s
mmt® is used in leaded gasoline.
1979
The Coordinating Research Council (CRC), a research organization comprising of oil and automobile industry sponsors, completed a comprehensive mmt® vehicle fleet test and concluded that the use of mmt® did not plug catalytic converters. To the contrary, the use of mmt® improved overall conversion efficiency of the catalytic converters.
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Asia Pacific
1987
The National Health and Medical Research Council of the Commonwealth of Australia reviewed the public health implications of mmt® and concluded that “there were no toxicological concerns over the use of mmt® in petrol.”
1999
China – National EPA of Peoples Republic of China and national specification approval for unleaded gasoline. Reaffirmed in 2004.
2000
Australian state approval for LRP.
2003
A risk assessment commissioned by Environment Australia concerning the use of mmt® as an anti-valve seat recession fuel additive concluded that “the overall risk to public health from the use of mmt®…is low.”
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Europe – Middle East - Africa
1997
Russia GOST approval A76 & A92. Reaffirmed in 2004.
1999
Government of France approval for unleaded and LRP.
1999
UK Government & British Standards Institute approval. In, 1999 the United Kingdom’s Committee on Toxicity of Chemicals in Food, Consumer Products and Environment was asked to consider the toxicological implications of the use of mmt® as a lead alternative in petrol. The Committee concluded that “the increase in ambient concentrations of manganese was unlikely to constitute a risk to health..”
2000
A risk assessment concerning the use of mmt® in South Africa found that “the introduction of mmt® in petrol in South Africa would have an insignificant effect on health risks relating to community exposure to manganese in airborne emissions from vehicle tailpipes” and “would make a very low contribution to the overall exposures of communities to manganese.” These conclusions were later reaffirmed in 2005.
2002
Automobile industry lobbying results in “metallic additives” being included in a European Review of fuel properties to be completed by the end of 2005. Ongoing mmt® use is allowed.
2005
European regulatory authorities propose development of a suitable test protocol for assessing metallic additives. Ongoing mmt® use is allowed.
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Latin America
1999
Argentina – IRAM (Government/Industry) specification approval for unleaded gasoline.
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North America
Canada
1970’s
Use of mmt® in U.S. and Canadian gasoline becomes widespread.
1978
Health and Welfare Canada issued the first of several risk assessments of mmt® in 1978. Health and Welfare Canada’s risk assessment concluded “that there is no evidence at present to indicate that expected ambient manganese concentrations [from use of mmt®] would constitute a hazard.” mmt® is approved for use at 18 mg Mn/litre in Canadian unleaded gasoline.
1986
The Royal Society of Canada undertook an assessment of alternatives to lead in 1986, including mmt®. Noting that mmt® had been in use in Canada in unleaded gasoline for eight years and that “[t]he additional exposure to manganese [from mmt®] is well within the normal range of dietary exposure,” the Royal Society conclude that “Coopers view (1984) that the general public has a wide margin of safety with respect to the worst case use of mmt® in gasoline appears to be sound.
1986
After review of mmt® use in Canadian gasoline, the Canadian General Standard Board (CGSB) concluded that “[t]he use of mmt® at current CGSB levels does not significantly compromise emission-control system operation or component durability.”
1990
Environment Canada comments to the U.S. EPA that “an examination of the manufacturer’s warranty claims did not reveal any abnormal incidence of [catalyst] plugging” in Canada since mmt®’s introduction.
1994
Health Canada issues a health risk assessment that reconfirms the acceptability of mmt®‘s use in gasoline stating “all analysis indicate that the combustion products of MMT® do not represent an added health risk to the Canadian population”.
1995-97
Afton commissions Research Triangle Institute with U.S. EPA input to conduct the world’s most comprehensive personal exposure study to measure manganese exposures in Toronto, Canada.
1997
Automobile industry lobbying results in a Canadian law banning importation of mmt® into Canada.
1998
The Canadian trade law is repealed following a successful challenge by Canadian Provincial Governments. Afton drops its then-pending NAFTA and constitutional legal challenges. The Government of Canada issues a statement confirming that “[c]urrent scientific information fails to demonstrate that mmt® impairs the proper functioning of automotive on-board diagnostic systems” and that ”there is no new scientific evidence to modify the conclusions drawn by Health Canada in 1994 that mmt® poses no health risk”.
2001
Responding to a citizen petition concerning the widespread use of mmt® in Canadian gasoline, Health Canada reaffirms the conclusions of its 1994 risk assessment for mmt®, noting that “the amount of scientific information on the neurotoxicology of and exposure to manganese is substantial compared to the equivalent information on the toxicity and potential exposures associated with some of the alternatives.”
2002
The automobile industry publishes the results of a low-emission vehicle (LEV) study. Despite automobile industry claims of concern, the data show no hardware problems and no statistically significant emission effects. The U.S. EPA and Environment Canada take no action despite fierce automobile industry lobbying.
2003
Afton obtains high level Canadian government briefing documents which state that “[i]n March 1997, the [auto] associations claimed that they had the proof required to show that MMT did harm emission control systems” and that the decision to rescind the mmt® trade restriction “was mainly due to the fact that the CVMA and AIAMC were not able to provide evidence supporting their claims that mmt® impairs emission control systems and harms the environment.”
2003
Environment Canada announces yet another review of mmt® to consider its effects on “Tier II” vehicle technologies. Review to follow the guidelines and regulations established in 1998 for any review arising from new information or allegations. The review is strongly supported by the oil industry and Afton in response to allegations by Honda of catalyst blocking, despite Honda’s refusal to share (with Afton) any data substantiating its allegations.
2005-06
Reports submitted by vehicle manufacturers to EPA of significant catalytic converter performance problems in North America occurring in 2000 and later model year vehicles unrelated to mmt® are uncovered.
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United States
1970’s
Use of mmt® in U.S. and Canadian gasoline becomes widespread.
1973
EPA’s efforts to remove lead from gasoline prompted an evaluation of manganese in 1973 because, as stated by the EPA, “[i]f lead is removed or reduced considerably in gasoline, the consumption of mmt® might increase significantly.” The EPA concluded that there was “a reasonable margin of safety with use of manganese in gasoline” because “[a]vailable evidence indicates that dosages required to produce…adverse effects are several orders of magnitude above those that would be present in the ambient air as a result of even the widespread use of manganese as a gasoline additive.”
1975
EPA issues two manganese evaluations in 1975. In the first report, the EPA concludes that “[t]here is no evidence that predicted manganese concentrations resulting from the use [mmt®] would result in adverse health effects.” The EPA concludes in the second report that “it is likely that the use of manganese in gasoline [does] not pos[e] a direct disbenefit to public health.” On this basis, the EPA acknowledges that “[t]he available data are insufficient to constitute a ’significant’ adverse effect…”
1978
The U.S. Clean Air Act is amended to require a waiver from EPA for use of non-hydrocarbon fuel components in unleaded gasoline, which provisionally prohibits use of mmt® in unleaded gasoline in the U.S..
1978
The U.S. EPA denies the first waiver application for mmt®.
1979
The U.S. EPA allows temporary use of mmt® to extend oil supplies.
1980’s
mmt® is used widely in leaded gasoline in the U.S. during the lead phase-down program.
1985
Near the time that mmt® use in leaded gasoline in the U.S. peaked, the EPA initiated a reevaluation of whether to regulate manganese emissions when it issued its “Health Assessment Document” for manganese in 1984. Later, in 1985 the EPA determined that “present ambient air concentrations of manganese [at levels as high as 4.1 ug/m3, or a level 100 times higher than upper level exposures in Canadian cities where mmt® has been widely used] do not pose a significant risk to public health and that no regulation directed specifically at manganese is necessary at this time under the Clean Air Act.”
1987
In June of 1984, Volkswagen requested that the EPA allow the use of a manganese emitting particulate trap for its diesel vehicles. In 1987, the EPA temporarily approved the request, and the Health Effects Institute, an independent body of scientists requested by the EPA to evaluate the Volkswagen request, concluded in 1988 that “it appears very unlikely that exposure to the levels of airborne manganese derived from automobile fuel additive as estimated in their report [i.e., 0.5ug/m3] would produce adverse neurologic effects.”
1989
In anticipation that a request would be made to approve use of mmt® as a bulk fuel additive in unleaded gasoline, the EPA’s Office of Mobile Sources completed an assessment of the health issues related to mmt® in 1989. One of the principal conclusions of the assessment was that “[i]t is unlikely that the presence of mmt® in gasoline would significantly contribute to the ambient particulate load.”
1990
Afton Chemical Corporation seeks a new U.S. EPA waiver based on extensive test fleet data. Data shows emission benefits in catalyst-equipped vehicles using mmt®.
1990
Environment Canada comments to the U.S. EPA that “an examination of the manufacturer’s warranty claims did not reveal any abnormal incidence of [catalyst] plugging” in Canada since mmt®’s introduction.
1993
EPA’s analysis of a second vehicle test fleet in support of the waiver application for mmt®, including Ford test vehicles, reconfirms emission benefits with use of mmt®. EPA concludes that mmt® “will not cause or contribute to the failure of any emission control device or system (over the useful life of the vehicle in which any such device or system is used)…”
1994
Based on a risk assessment conducted by the EPA with regard to the widespread use of mmt® in Canadian gasoline, the EPA concluded that no evidence existed to indicate that use of mmt® would present a significant risk to public health. The EPA indicated, however, that a “reasonable basis for concern” was raised because the EPA’s best estimate of manganese exposures with use of mmt® fell “in the vicinity of or exceed[ed] the RfC.” Noting that “[e]xeeding the RfC does not necessarily indicate that a public health risk will occur,” the EPA indicated that additional testing, including exposure testing, would “provide greater assurance that manganese emissions would not jeopardize public health.” The EPA is currently reassessing the conclusions of its 1994 risk assessment in light of the very low manganese exposures measured in the Toronto exposure study.
1995
The U.S. Court of Appeals confirmed the use of mmt® for the U.S. market when the court ruled that the “administrator of the EPA exceeded her authority” and "violated the clear terms of section 211(f) (4) [of the U.S. Clean Air Act] in denying Ethyl a waiver for mmt®." mmt® is approved for use in unleaded gasoline in the US.
1995-97
Afton commissions Research Triangle Institute with U.S. EPA input to conduct the world’s most comprehensive personal exposure study to measure manganese exposures in Toronto, Canada.
1996-97
Afton commissions Lawrence Livermore National Laboratory with U.S. EPA input to re-examine the species of manganese in vehicle tailpipe emissions.
1997
Tier 1 health data submitted to the U.S. EPA for mmt®.
2000-2005
The U.S. EPA finalizes Tier 2 health testing requirements for base gasoline, MTBE, oxygenates and other fuel components, including mmt®. Afton commissions a test program led by the Chemical Industry Institute of Toxicology (CIIT).
2002
The automobile industry publishes the results of a low-emission vehicle (LEV) study. Despite automobile industry claims of concern, the data show no hardware problems and no statistically significant emission effects. The U.S. EPA and Environment Canada take no action despite fierce automobile industry lobbying.
2004
Testing in the U.S. EPA mandated Tier 2 health program is completed and the program moves into the final modeling stage expected to last into 2007. The scientific studies indicate that there is no increased health risk associated with the use of mmt®. The studies are available on the EPA web site. mmt® remains approved for use by the U.S. EPA.
2005-06
Reports submitted by vehicle manufacturers to EPA of significant catalytic converter performance problems in North America occurring in 2000 and later model year vehicles unrelated to mmt® are uncovered.
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