| Revision as of 15:50, 25 August 2011 edit63.103.224.1 (talk) →History← Previous edit |
Latest revision as of 20:40, 7 June 2024 edit undoAnDeargMor (talk | contribs)Extended confirmed users797 edits Edited model to cation structure. Not sure how to make it have trigonal pyramid structure |
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| ImageFile = MMT-2D-skeletal.png |
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| ImageFile = Methylcyclopentadienyl-Manganese-Tricarbonyl_Skeletal.svg |
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| ImageSize = 130px |
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| ImageFile1 = MMT-3D-balls.png |
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| ImageSize = 250px |
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| ImageFile1 = MMT-3D-balls.png |
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| ImageSize1 = 150px |
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| ImageSize1 = 150px |
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| IUPACName = tricarbonyl(methyl-η<sup>5</sup>-<br />cyclopentadienyl)manganese |
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| IUPACName = tricarbonyl(methyl-η<sup>5</sup>-<wbr />cyclopentadienyl)manganese |
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| OtherNames = MMT, CI-2, Combustion Improver-2, Manganese tricarbonylmethylcyclopentadienyl, 2-Methylcyclopentadienyl manganese tricarbonyl |
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| OtherNames = MMT |
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| Section1 = {{Chembox Identifiers |
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|Section1={{Chembox Identifiers |
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| CASNo_Ref = {{cascite|correct|??}} |
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| SMILES = |
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| CASNo = 12108-13-3 |
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| CASNo = 12108-13-3 |
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| RTECS = OP1450000 |
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| RTECS = OP1450000 |
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| PubChem = 11986208 |
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| UNII = 1E52JN2L3I |
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| EINECS = 235-166-5 |
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| UNNumber = 3281 |
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| ChemSpiderID = 23801 |
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| StdInChI=1S/C6H7.3CO.Mn/c1-6-4-2-3-5-6;3*1-2;/h2-5H,1H3;;;;/q-1;;;; |
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| StdInChIKey = IYSGJCJSRBFZSZ-UHFFFAOYSA-N |
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| SMILES = CC1=CC=C1.#C(C#)C# |
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| Section2 = {{Chembox Properties |
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|Section2={{Chembox Properties |
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| Formula = C<sub>9</sub>H<sub>7</sub>MnO<sub>3</sub> |
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| Formula = C<sub>9</sub>H<sub>7</sub>MnO<sub>3</sub> |
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| MolarMass = 218.09 g/mol |
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| MolarMass = 218.09 g/mol |
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| Appearance = pale yellow liquid<br />herbaceous odor |
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| Appearance = pale yellow to dark orange liquid<ref name=PGCH/> |
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| Odor = faint, pleasant<ref name=PGCH>{{PGCH|0409}}</ref> |
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| Density = 1.38 g/cm³ |
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| Density = 1.38 g/cm<sup>3</sup> |
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| Solubility = low |
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| Solubility = low{{vague|date=March 2022}} |
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| Solvent = other solvents |
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| Solvent = |
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| SolubleOther = ] (petrol) |
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| SolubleOther = Hydrocarbons (petrol), ether, alcohol, THF |
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| MeltingPt = -1 °C (272 K) |
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| BoilingPt = 232-233 °C |
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| MeltingPtC = -1 |
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| Viscosity = |
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| MeltingPt_notes = |
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| BoilingPtC = 232 to 233 |
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| VaporPressure = 7 mmHg (100°C)<ref name=PGCH/> |
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| Section3 = {{Chembox Structure |
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|Section3={{Chembox Structure |
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| Coordination = Tetrahedral at Mn |
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| Coordination = Tetrahedral at Mn |
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| CrystalStruct = <!-- e.g. ], ], ], ], ], ], ], and mention "close packed" or similar. You may also cite what class it belongs to, e.g. ] --> |
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| CrystalStruct = <!-- e.g. ], ], ], ], ], ], ], and mention "close packed" or similar. You may also cite what class it belongs to, e.g. ] --> |
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| Section7 = {{Chembox Hazards |
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| GHSPictograms = {{GHS06}}{{GHS09}} |
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| MainHazards = flammable |
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| GHSSignalWord = Danger |
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| FlashPt = 205 °F |
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| HPhrases = {{H-phrases|301|310|330|315|372|410}} |
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| RPhrases = 23/24/25-40 |
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| PPhrases = {{P-phrases|260|273|280|284|301+310|302+350}} |
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| SPhrases = 23-26-36/37/39-45 |
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| MainHazards = Flammable, toxic |
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| FlashPtF = 230 |
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| FlashPt_ref = <ref name=PGCH/> |
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| PEL = C 5 mg/m<sup>3</sup><ref name=PGCH/> |
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| IDLH = N.D.<ref name=PGCH/> |
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| REL = TWA 0.2 mg/m<sup>3</sup> <ref name=PGCH/> |
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| Section8 = {{Chembox Related |
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| OtherCpds = ]<br />]<br /> ] |
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| OtherCompounds = ]<br />]<br /> ] |
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'''Methylcyclopentadienyl manganese tricarbonyl''' ('''MMT''' or '''MCMT''') is an ] with the formula (C<sub>5</sub>H<sub>4</sub>CH<sub>3</sub>)Mn(CO)<sub>3</sub>. Initially marketed as a supplement for use in leaded ], MMT was later used in unleaded gasoline to increase the ]. Following the implementation of the ] (CAA) in 1970, MMT continued to be used alongside ] (TEL) in the US as leaded gasoline was phased out (prior to TEL finally being banned from US gasoline in 1995), and was also used in unleaded gasoline until 1977. ] obtained a waiver from the U.S. EPA (Environmental Protection Agency) in 1995, which allows the use of MMT in US unleaded gasoline (not including reformulated gasoline) at a treat rate equivalent to 8.3 mg Mn/L (manganese per liter).<ref>{{Cite web|url=https://www.gpo.gov/fdsys/granule/FR-1995-07-17/95-17476/content-detail.html|title=60 FR 36414 - Fuels and Fuel Additives; Grant of Waiver Application}}</ref> |
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MMT has been used in Canadian gasoline since 1976 (and in numerous other countries for many years) at a concentration up to 8.3 mg Mn/L (though the importation and interprovincial trade of gasoline containing MMT was restricted briefly during the period 1997–1998)<ref>{{Cite news|title=Threat of NAFTA Case Kills Canada's MMT Ban: Challenge over gasoline additive could have cost Ottawa millions|date= July 20, 1998 |work= The Globe and Mail }}</ref><ref>{{Cite web|url=http://leiss.ca/wp-content/uploads/2009/12/mmt_a_risk_management_masquerade.pdf|title=MMT, A Risk Management Masquerade}}</ref> and was introduced into ] in 2000. It has been sold under the tradenames HiTEC 3000, Cestoburn and Ecotane.<ref>{{Cite journal|last=Frumkin|first=Howard|date=1997|title=Manganese in the US Gas Supply|journal=American Journal of Industrial Medicine |volume=31 |issue=1|pages=107–115|doi=10.1002/(SICI)1097-0274(199701)31:1<107::AID-AJIM16>3.0.CO;2-6|pmid=8986262|display-authors=etal}}</ref><ref>{{cite news |last1=Patterson |first1=Steve |title=Report: Owners of Jacksonville's T2 Lab never knew risks of deadly explosion |url=https://www.jacksonville.com/story/news/2009/09/15/report-owners-of-jacksonvilles-t2-lab-never-knew-risks-of-deadly-explosi/15973372007/ |access-date=1 December 2022 |work=The Florida Times-Union |date=15 September 2009 |archive-url=https://web.archive.org/web/20221201010302/https://www.jacksonville.com/story/news/2009/09/15/report-owners-of-jacksonvilles-t2-lab-never-knew-risks-of-deadly-explosi/15973372007/ |archive-date=1 December 2022|url-status=live |language=en-US}}</ref> MMT is also used in ].<ref>{{cite journal |doi=10.1016/j.fuel.2014.12.064|title=Combustion and emission characteristics of a direct-injection gasoline engine using the MMT fuel additive gasoline |year=2015 |last1=Geng |first1=Peng |last2=Zhang |first2=Hui |journal=Fuel |volume=144 |pages=380–387 }}</ref> |
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'''Methylcyclopentadienyl manganese tricarbonyl (MMT or MCMT)''' is an ] with the formula (CH<sub>3</sub>C<sub>5</sub>H<sub>4</sub>)Mn(CO)<sub>3</sub>. Marketed initially in 1958 as a supplement to the ] ] to increase the fuel's ], MMT was later used in unleaded gasoline.<ref name="MMTHistoryatAfton">http://www.aftonchemical.com/Products/MMT/History+of+MMT.htm</ref> Although banned as a gasoline additive in the United States from 1977 to 1995, MMT has been used in Canadian gasoline since 1976 (though was banned from 1997-1998 due to safety concerns)<ref name="CanadianBan">''The Globe and Mail'' "Threat of NAFTA Case Kills Canada's MMT Ban: Challenge over gasoline additive could have cost Ottawa millions". July 20, 1998</ref> and was recently introduced in ]. It is sold under the tradenames HiTEC® 3000 and AK-33X.<ref name=Frumkin>Frumkin, Howard and Solomon, Gena; "Manganese in the US Gas Supply" American Journal of Industrial Medicine, 31: 107-115 (1997)</ref> It is also marketed as Ecotane by ].<ref name=t2labs>{{cite web | url=http://www.t2labs.com/ecotane/ecotane.htm | title=T2 Labs is the manufacturer of Ecotane | accessdate=December 20, 2007 }}</ref> |
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==History== |
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== History of usage in the United States == |
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Tetraethyl lead (TEL) has been, and still is, used as an additive to increase the octane rating of gasoline. TEL was manufactured and marketed by the ], a joint venture between ] and ]. When the US ] (EPA) ordered the phasing out of leaded gasoline in 1972, new fuel additives were sought. Initially marketed in 1958 as a smoke suppressant for ]s, MMT was used in 1974 as an additive in unleaded gasoline. |
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Although initially marketed in 1958 as a smoke suppressant for gas turbines, MMT was further developed as an octane enhancer in 1974. When the ] (EPA) ordered the phase out of TEL in gasoline in 1973, new fuel additives were sought. TEL has been used in certain countries as an additive to increase the octane rating of automotive gasoline but has been phased out in all countries since July 2021.<ref>{{cite news |title=End of leaded fuel use a 'milestone for multilateralism' |url=https://news.un.org/en/story/2021/08/1098792 |access-date=5 March 2022 |work=UN News |date=30 August 2021 |language=en}}</ref> |
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In 1977, the US Congress amended the CAA to require advance approval by the EPA for the continued use of fuel additives such as MMT, ], ethyl tert-butyl ether (]), etc.<ref>{{Cite web|url=https://www.law.cornell.edu/uscode/text/42/7545|title=42 USC § 7545 - Regulation of fuels}}</ref> The new CAA amendment required a "waiver" to allow use of fuel additives made of any elements other than carbon, hydrogen, oxygen (within certain limits) and nitrogen.<ref>Definition of Substantially Similar.</ref> To obtain a waiver, the applicant was required to demonstrate that the fuel additive would not lead to a failure of vehicle emission control systems. |
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In 1977, use of MMT was banned in the US by the ] until the Ethyl Corporation could prove that the additive would not lead to failure of new car emissions-control systems. As a result of this ruling, the Ethyl Corporation began a legal battle with the EPA, presenting evidence that MMT was harmless to automobile emissions-control systems. In 1995, the U.S. Court of Appeals ruled that the EPA had exceeded its authority and, as a result, MMT became a legal fuel additive in the US.<ref name=Kitazawa>Masashi Kitazawa, Jarrad R. Wagner, Michael L. Kirby, Vellareddy Anantharam, and Anumantha G. Kanthasamy; ''Oxidative Stress and Mitochondrial-Mediated Apoptosis in Dopaminergic Cells Exposed to Methylcyclopentadienyl Manganese Tricarbonyl'' J. Pharmacol. Exp. Ther., Jul 2002; 302: 26 - 35.</ref> MMT is currently manufactured by the Afton Chemical Corporation, a subsidiary of ].<ref name="MMTHistoryatAfton"/> It is also produced and marketed as "Cestoburn" by Cestoil Chemical Inc. in Canada. |
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Ethyl Corporation applied to the US EPA for a waiver for MMT in both 1978 and 1981; in both cases the applications were denied because of stated concerns that MMT might damage catalytic converters and increase hydrocarbon emissions. In 1988, Ethyl began a new series of discussions with the EPA to determine a program for developing the necessary data to support a waiver application. In 1990, Ethyl filed its third waiver application prompting an extensive four-year review process. In 1993, the U.S. EPA determined that use of MMT at 8.3 mg Mn/L would not cause, or contribute to, vehicle emission control system failures.<ref>58 Fed. Reg. 64,761 (December 9, 1993)</ref> |
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==Structure and bonding== |
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The compound is called a piano-stool or half-]. The ] atom in MMT is bonded to three ] as well as to the ] ring. These hydrophobic organic ligands make MMT highly lipophilic, which may increase ]. A variety of related complexes are known, including ], which is also under consideration as an additive to gasoline.{{Citation needed|date=December 2008}} <!--says who?--> |
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Despite that finding, the EPA ultimately denied the waiver request in 1994 due to uncertainty related to health concerns regarding manganese emissions from the use of MMT.<ref>{{Cite web|url=https://www.gpo.gov/fdsys/pkg/FR-1994-08-17/html/94-18941.htm|title=Fuels and Fuel Additives;Waiver Decision/Circuit Court Remand}}</ref> |
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==Preparation== |
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]<ref name=MMTPatent>{{US patent|4946975}}</ref> |
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As a result of this ruling, Ethyl initiated a legal action claiming that the EPA had exceeded its authority by denying the waiver on these grounds. This was upheld by the US Court of Appeals<ref>{{Cite web|url=http://openjurist.org/51/f3d/1053/ethyl-corporation-v-environmental-protection-agency|title=Waiver Ruling|date=13 January 1995|volume=F3d|issue=51|page=1053}}</ref> and EPA subsequently granted a waiver which allows the use of MMT in US unleaded gasoline (not including reformulated gasoline) at a treat rate equivalent to 8.3 mg Mn/L. |
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==Related compounds== |
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The related compound CpMn(CO)<sub>3</sub> is also well studied as well as the corresponding thiocarbonyl derivatives CpMn(CS)<sub>2</sub>CO and CpMn(CS)(CO)<sub>2</sub>.<ref>Petz, W., "40 years of transition-metal thiocarbonyl chemistry and the related CSe and CTe compounds", Coordination Chemistry Reviews, 2008, 252, 1689-1733.{{DOI|10.1016/j.ccr.2007.12.011}}.</ref> |
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Implementation of this alternative to TEL has been controversial. ] compounds have, in general, very low toxicity, but their combustion products still ] ]s. Opposition from automobile manufacturers and some areas of the scientific community has reportedly prompted oil companies to stop voluntarily the usage of MMT in some of their countries of operation.<ref>{{Ullmann|first1=Marco|last1=Di Girolamo|first2=Maura|last2=Brianti|first3=Mario|last3=Marchionna|title=Octane Enhancers|doi=10.1002/14356007.a18_037.pub3}}</ref> |
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MMT is currently manufactured in the U.S. by the ] Corporation, a subsidiary of New Market Corporation.<ref>{{Cite web|url=http://www.aftonchemical.com/Solutions/FuelAdd/Octane_Improver/Pages/Octane%20Improver.aspx|title=Afton Chemical Ltd}}</ref> It is also produced and marketed as Cestoburn by Cestoil Chemical Inc. in Canada. |
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==Structure and synthesis== |
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MMT is manufactured by reduction of bis(methylcyclopentadienyl) manganese using ]. The reduction is conducted under an atmosphere of ]. The reaction is ], and without proper cooling, can lead to catastrophic ].<ref>{{cite web|title=T2 Laboratories Inc. Reactive Chemical Explosion|url=http://www.csb.gov/t2-laboratories-inc-reactive-chemical-explosion/|website=US Chemical Safety Board|publisher=USCSB|accessdate=29 April 2016}}</ref> |
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MMT is a so-called ], or more specifically a "piano-stool" complex (since the three CO ligands are like the legs of a stool). The ] atom in MMT is coordinated with three ] as well as to ] of the ] ring. These hydrophobic organic ligands make MMT highly lipophilic. |
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A variety of related complexes are known, including ], which has also been used as an additive to gasoline. Many derivatives of MMT are known.<ref>Petz, W., "40 years of transition-metal thiocarbonyl chemistry and the related CSe and CTe compounds", Coordination Chemistry Reviews, 2008, volume 252, pp. 1689-1733.]:].</ref> |
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==Safety== |
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==Safety== |
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The human and environmental health impacts that may result from the use of MMT will be a function of exposure to either: (1) MMT in its original, unchanged, chemical form and/or (2) manganese combustion products emitted from vehicles operating on gasoline containing MMT as an octane improver. |
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The health hazards associated with MMT have been hotly debated for decades. A 2003 study by the NICNAS in Australia suggested that MMT was highly toxic to humans in raw concentrated form, but ruled that the airborne concentrations of manganese as a result of car emissions from vehicles using fuel containing MMT posed no health hazard.<ref name=NINCAS>National Industrial Chemicals Notification and Assessment Scheme; ''Methylcyclopentadienyl Manganese Tricarbonyl'' June 2003. </ref> A 2002 study by Masashi Kitazawa argued that dermal absorption from accidental gasoline spills, misuse of gasoline as a solvent cleaner, and deliberate ] were the main sources of potential MMT exposure. |
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===Pre-combustion storage and handling=== |
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Chronic exposure to manganese has been known to cause ]. The symptoms of manganism are similar to those of ]. MMT has been shown to be ] and especially damaging to dopaminergic PC-12 cells.<ref name=Kitazawa/> ] studies have shown that manganese derived from MMT absorbs into rat blood plasma at a rate 37 times that of inorganic manganese.<ref name=Zheng>{{cite journal |author=Zheng W, Kim H, Zhao Q |title=Comparative toxicokinetics of manganese chloride and methylcyclopentadienyl manganese tricarbonyl (MMT) in Sprague-Dawley rats |journal=Toxicol. Sci. |volume=54 |issue=2 |pages=295–301 |year=2000 |month=April |pmid=10774811 |doi= 10.1093/toxsci/54.2.295|url=http://toxsci.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=10774811}}</ref> |
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The general public has minimal direct exposure to MMT. As stated by the US EPA in their risk assessment on MMT, "except for accidental or occupational contacts, exposure to MMT itself was not thought likely to pose a significant risk to the general population."<ref>{{cite journal |last1=Davis |first1=J. M |last2=Jarabek |first2=A. M. |last3=Mage |first3=D. T. |last4=Graham |first4=J. A. |title=The EPA health risk assessment of methylcyclopentadienyl manganese tricarbonyl (MMT) |journal=Risk Assessment |date=Feb 1998 |volume=18 |issue=1 |pages=57–70 |doi=10.1111/j.1539-6924.1998.tb00916.x |pmid=9523444 |url=https://pubmed.ncbi.nlm.nih.gov/9523444/ |access-date=25 June 2023}}</ref> Similarly, the Australian National Industrial Chemicals Notification and Assessment Scheme (NICNAS) stated that "inimal public exposure to MMT is likely as a result of spills and splashes of LRP and aftermarket additives".<ref>{{Cite web|url=http://www.nicnas.gov.au/__data/assets/pdf_file/0020/4385/PEC_24_Methylcyclopentadienyl-Manganese-Tricarbonyl-MMT_Full_Report_PDF.pdf|title=National Industrial Chemicals Notification and Assessment Scheme; Methylcyclopentadienyl Manganese Tricarbonyl June 2003|url-status=dead|archive-url=https://web.archive.org/web/20150327015831/http://www.nicnas.gov.au/__data/assets/pdf_file/0020/4385/PEC_24_Methylcyclopentadienyl-Manganese-Tricarbonyl-MMT_Full_Report_PDF.pdf|archive-date=2015-03-27}}</ref> |
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The MMT dossier registered in the European Chemical Agency's webpage indicates that before combustion in gasoline, MMT is classified as an acute toxicant by the oral, dermal, and inhalation routes of exposure under the European Union's Classification, Labeling and Packaging Regulation (EC/1272/2008), implementing the ]. The US ATSDR (Agency for Toxic Substances and Disease Registry) notes that MMT is very unstable in light and degrades to a mixture of less harmful substances and inorganic manganese in less than 2 minutes.<ref>{{Cite journal|last=Garrison|first=AW|date=1995|title=Environmental fate of methylcyclopentadienyl manganese tricarbonyl|journal=Environmental Toxicology and Chemistry |volume=14 |issue=11 |pages= 1859–1864|doi=10.1002/etc.5620141107|display-authors=etal}}</ref><ref>{{Cite journal|last=Wallington|first=TJ|date=1999|title= Atmospheric Chemistry of Methylcyclopentadienyl Manganese Tricarbonyl: Photolysis, Reaction with Hydroxyl Radicals and Ozone|journal= Environmental Science & Technology|volume=33 |issue= 23|pages= 4232–4238|doi=10.1021/es990350p|bibcode=1999EnST...33.4232W}}</ref> Therefore, human exposure to MMT prior to combustion in gasoline would not likely occur at significant levels. |
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Immediate symptoms of MMT exposure are mild skin and eye irritation. Short-term symptoms resulting from MMT poisoning include giddiness, headache, nausea, and difficulties in breathing. Animal studies have shown that long-term exposure to MMT can result in damage to the liver and kidneys.<ref name=WorldHealth>United Nations Environment Programme with the ]; ''Manganese''; Geneva, 1981.</ref> |
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The US OSHA (]) has not established a permissible exposure limit specifically for MMT. However, OSHA has set a ] at a ceiling of 5 mg/m<sup>3</sup> for manganese and its compounds, while the ] ] workers not be exposed to more than 0.2 mg/m<sup>3</sup>, over an eight-hour time-weighted average.<ref>{{Cite web|url=https://www.cdc.gov/niosh/npg/npgd0409.html|title=NIOSH Pocket Guide to Chemical Hazards. Centers for Disease Control and Prevention. April 4, 2011. Retrieved November 19, 2013}}</ref> In Europe, the MMT DNELs (Derived No Effect Level) for workers by the inhalation and dermal routes of exposure are 0.6 mg/m<sup>3</sup> and 0.11 mg/kg-day, respectively. The MMT DNELs for the general population by the inhalation and dermal routes of exposure are 0.11 mg/m<sup>3</sup> and 0.062 mg/kg-day, respectively. |
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==Vehicle Manufacturer Recommendations== |
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Before using MMT, you should first determine whether or not the manufacturer recommends use in the vehicle. Some manufacturers recommend against use of MMT in their vehicles.<ref name=GM>General Motors, "2011 Chevrolet Malibu Owners Manual", 2010. </ref> |
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===Combustion products=== |
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In 1994 (reaffirmed in 1998, 2001 and 2010), ] concluded that "airborne manganese resulting from the combustion of MMT in gasoline powered vehicles is not entering the Canadian environment in quantities or under conditions that may constitute a health risk"<ref>{{Cite web|url=http://www.oag-bvg.gc.ca/internet/English/pet_032_e_28732.html|title=Petition to the Commissioner of the Environment and Sustainable Development, under section 22 of the Auditor General Act. July 2001|access-date=2011-09-09|archive-date=2017-06-14|archive-url=https://web.archive.org/web/20170614012514/http://www1.oag-bvg.gc.ca/internet/English/pet_032_e_28732.html|url-status=dead}}</ref> and confirmed they were taking no action with respect to MMT. Similarly, the 2003 NICNAS report states that the airborne concentrations of manganese as a result of car emissions from vehicles using fuel containing MMT poses no health hazard.{{Citation needed|date=October 2020}} |
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The assessment conducted by NICNAS asserts that "anganese, the principle degradation by-product from combustion of MMT, is naturally occurring and ubiquitous in the environment. It is an essential nutrient of plants and animals. Environmental exposure to Mn compounds will mostly arise through the gaseous phase. Eventually, these will deposit to land and waters. The emission of Mn into the environment from use of fuels containing MMT is unlikely to develop to levels of concern and therefore poses a low risk for terrestrial or aquatic environments." |
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Additional health studies, overseen by the US EPA, were conducted to explain the transport of manganese in the body. In studies published from 2007 through 2011, no significant health effects are anticipated from the use of MMT in gasoline.<ref>{{Cite web|url=https://www.regulations.gov/#!documentDetail;D=EPA-HQ-OAR-2004-0074-0153|title=Methylcyclopentadienyl Manganese Tricarbonyl (MMT) Alternative Tier 2 Health Effects Test Program, Docket EPA-HQ-OAR-2004-0074}}</ref> |
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=== Overall combined risk assessment === |
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Based on the low potential for the release of concentrated MMT (before its combustion in gasoline) under normal storage and use, as well as its rapid photo-degradation properties, it has been concluded in multiple technical and global regulatory assessments that significant impacts to human health or the environment from MMT use are not anticipated. NICNAS concluded that there is "low occupational risk associated with MMT" both "for workers involved in formulating and distributing LRP or aftermarket fuel additives and those involved in automotive maintenance". Further, they also concluded that there is a "low risk" to the public from the use of MMT. |
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Significant human or environmental exposures associated with manganese compounds (manganese phosphate, manganese sulfate and manganese dioxide) from the combustion of MMT are not expected. In Health Canada's risk assessment on the health implications of the manganese combustion products of MMT, it was concluded that manganese exposures from MMT use are unlikely to pose a risk to health for any sub-group of the population. NICNAS similarly concluded that chronic Mn exposures (from all sources combined) are unlikely to be significantly changed by the use of MMT as a fuel additive. |
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In 2013, a risk assessment on MMT was developed by ARCADIS Consulting and verified by an independent panel, according to the methodology provided by the European Commission in compliance with the requirements of the European Fuel Quality Directive (2009/30/EC). The conclusions of a risk assessment are that "for MMT and its transformation products, when MMT is used as a fuel additive in petrol, no significant human health or environmental concerns related to exposure to either MMT or its transformation products (manganese phosphate, manganese sulfate and manganese tetroxide) were identified at use at levels up to 18 mg Mn/L. Depending on the regional needs and the vehicle emission control technology available, an MMT treat rate in the range of 8.3 mg Mn/L to 18 mg Mn/L is scientifically justified and may deliver both environmental and economic benefits without significant adverse effects."<ref></ref> |
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==T2 Laboratories explosion and fire== |
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{{Main|T2 Laboratories explosion and fire}} |
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On December 19, 2007 an ] occurred in the production of MMT in Florida, which killed four people and injured fourteen.<ref name="report">{{cite web |title=Investigation Report Report: T2 Laboratories, Inc. Runaway Reaction |url=https://www.csb.gov/userfiles/file/t2%20final%20report.pdf |website=www.csb.gov |publisher=United States Chemical Safety and Hazard Investigation Board |access-date=30 November 2022 |language=en-US |date=15 September 2009|number=2008-3-I-FL}}</ref> |
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==See also== |
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*] |
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==References== |
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==References== |
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{{reflist|2}} |
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{{reflist|30em}} |
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{{manganese compounds}} |
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