Relative risk of MMT use versus other fuel properties

Road Map’s selective recommendation ignores the inherent risks that are known with certainty to exist from fuel combustion, and that are subject of ongoing scientific studies and regulatory evaluation in Canada and the United States.A balanced assessment of all the available science does not support the Road Map’s recommendation against the use of MMT ®. There is no basis in fact to do so. In fact, as the Road Map makes clear, fuel combustion entails inherent risks no matter how the fuel is composed. These inherent risks cannot be ignored when assessing the relative merit of the different options currently available to refiners to produce cleaner burning fuel. Decisions on fuel composition should be based on comparative assessments of different risk trade-offs. Yet when the Road Map invokes the “precautionary principle”, it does so in a manner that holds one option (i.e. MMT®) to a different standard than all other options, and recommends that refiners avoid use of metallic additives in general and MMT® in particular.This recommendation against the use of MMT® ignores the inherent risks that are known with certainty to exist from fuel combustion (e.g., benzene and 1,3 butadiene emissions). The recommendation also gives completely disproportionate weight to potential concerns that might be associated with use of MMT® even though, as explained in Afton’s earlier comments, use of MMT ® has the undeniable potential in appropriate cases to reduce some of known risks from fuel combustion (as has been verified by respected regulatory agencies around the world).For this reason, the recommendation against use of MMT® is unwarranted. It creates the grave and real risk that, based on the Road Map’s recommendations, some stakeholders will formulate fuels that are clearly more harmful than they would have been if MMT® had been one of the options available to them.MMT reduces the contents of hazardous components in gasolineIn the case of MMT ®, manganese is an unavoidable emission by-product when it is available as a blending option to refiners, but refiners and gasoline blenders using MMT ® can reduce or eliminate other components in gasoline that increase the emission of one or more of the substances identified by EPA to be of most “concern”. When MMT® is not an option, the converse is true. Refiners and gasoline blenders must use alternative blending components, such as MTBE, ethanol, olefins, or aromatics, which will increase emissions of one or more of the other substances known to be toxic. In short, as Afton Chemical explained in its prior comments, trade-offs are inevitable when formulating gasoline.
Responses:
MMT is added to fuel while some of the elements referred to by Afton are natural ingredients in fuel. The Road Map has adopted an approach that calls for reduction in the harmful impact of natural elements in fuel through a combination of:Refining techniques to minimize the presence of harmful natural elements in gasoline (e.g. benzene)The introduction of emission control devices such a catalytic converters and particulate filters, together these devices will further reduce harmful elements in the tailpipe emissionsThe lowering of sulfur in gasoline and diesel to enable the use of these advanced emission control devices.The use of MMT undermines such a strategy and is counterproductive: (a) it adds potentially harmful substances to the gasoline pool, with concerns about health effects, and (b) it has impacts on the functioning of advanced emission control devices, reducing their effectiveness in controlling other harmful emissions.
The references by Afton on actual aromatic reductions of 1.6% with the use of MMT, from a 1994 study, appear to be no longer relevant because of various changes in overall fuel composition and especially changes in engine and emission control device technology.
The use of emission control devices such as catalytic converters (gasoline), particulate filters (diesel) and supportive on-board diagnostic systems are an important, if not the most important, part of the technological strategy to reduce vehicle emissions. It is this approach which is affected by the use of MMT because it reduces the effectiveness of these systems. It seems counterproductive for Asian countries to promote the use of a fuel additive that prevents the effective deployment of emission control technology when there are alternative fuel additives and fuel production technologies available that are cost effective and which do not cause any risk of affecting the effectiveness of emission control devices.
Afton comments that if MMT is not used (i) there is no other option than to use oxygenates, and (ii) the use of oxygenates is more harmful than the use of MMT. As the Road Map explains the preferred option is to modify the refining process to achieve the required octane levels, thereby avoiding the need for any additive. This is the preferred option especially in the case of refinery expansion. As explained in the Road Map document it is not believed that the use of oxygenates will result in increases of toxic emissions that are dangerous and which should lead to avoidance of the use of oxygenates.
Modifications to the Road Map
No modifications to the Road Map were made in this respect.
D. Impact of the use of MMT on emission control systems
Commentsn the sentific record for MMT® and its potential impact on vehicle performance is also voluminous. In addition to numerous vehicle fleet tests conducted by automakers, the producer of MMT®, and others, the impact of MMT® on the operation of the major components of vehicle engine and emission control systems (i.e., spark plugs, fuel injectors, intake and exhaust valves, catalytic converters, and oxygen sensors, etc,) has been the subject of a wide range of studies. MMT® also has a long and established record of acceptable performance in commercial use in Canada, the U.S. and elsewhere around the world. As in the case of potential public health concerns, more than ample scientific data exist to make reasonable scientific judgments about MMT®’s compatibility with advanced vehicle emission control systems. A summary of some of the key conclusions of the numerous technical reviews of MMT® that have occurred over the past several decades is presented in Table III.
The Road Map makes no attempt either to report the full extent of scientific information available for MMT® or to assess the meaning of the voluminous data. Instead, the Road Map refers only to the 2002 vehicle manufacturer study of MMT® to support claims that MMT® increases emissions, reduces fuel economy, and causes catalyst plugging. Although all of these claims have been directly refuted in peer-reviewed scientific papers ignored by the Road Map’s authors, the most telling fact has also been ignored. In July of 2002, automakers formally petitioned EPA and officials in the Canadian government to ban the use of MMT® based on the results of the 2002 automaker study. Those petitions were rejected. As a result, MMT® remains a legal fuel additive for use in both Canada and the U.S. Responses:The Alliance of Automotive Manufacturers disputes the submission of a formal petition to US-EPA. Afton's suggestion that "[a]s the result" of these actions by the vehicle industry, "MMT remains a legal fuel additive for use in both Canada and the U.S." is misleading. MMT is banned in California, and it cannot be used in any reformulated gasoline that is mandated at the federal level. The Canadian government not initiating an independent review of the effects of MMT on vehicle emissions and advanced emission control systems, so far, is likely attributable to the fact that Canadian refiners began to voluntarily phase out the use of MMT in 2005, and that its present-day usage in the Canadian fuel market is virtually zero. A similar voluntary phase out of the use of MMT in the USA (apart from California and the reformulated gasoline market, where the use of MMT is not allowed) has also resulted in a situation that the overall present-day usage of MMT in the USA fuel market is virtually zero. MMT was used in Australia for a short period from 2001 to 2004 in a selectively marketed Lead Replacement Gasoline, the marketing of which was discontinued due to poor demand. MMT was not used in unleaded gasoline, the most widely used product, or in other brands of Lead Replacement Gasoline. These voluntary actions by the fuel industry in Australia, Canada and the USA were not pursued due to any regulatory forcing function.
The global vehicle industry, through regional associations in Japan, Europe and the USA periodically issues its recommendations on required fuel characteristics through the World Wide Fuel Charter (WWFC). The most recent 2006 version of the Charter states “Today’s vehicles employ sophisticated emission control equipment such as three-way catalysts and exhaust gas oxygen sensors to provide precise closed-loop control. These systems must be kept in optimal condition to maintain low emissions for the lifetime of the vehicle. Ash-forming (metal-containing) additives can adversely affect the operation of catalysts and other components, such as oxygen sensors, in an irreversible way that increases emissions. Thus, high-quality gasoline should be used and ash-forming additives must be avoided.” MMT is metal-based (manganese) and therefore is ash-forming during the combustion process and falls under the category of additives to be avoided.The published body of evidence on this topic is still limited. The majority of the studies quoted by Afton date back to 1986, 1990, 1994, and 1998 Only one study has been quoted from 2006 (PRC). This study was based on a small sample of 6 vehicles. It is important to differentiate in the studies that have been published between the specific nature of the emission control device used and the reference fuel used. There has been, and still is a fast development in the types and technical specifications of catalysts being used. Internationally the trend is towards catalysts with a higher cell count. Such catalysts are required to realize the emission reductions required under the Euro 4 and beyond standards. The comment of Afton that the use of MMT does not impact catalytic converters is contradicted by a large body of visual evidence in the form of photographs on the impact of MMT on in-use catalysts and subsequent confirmation that the deposits on the face of the catalysts was manganese-based. Also, SAE paper (2007-01-1070) provides empirical data on the relationship between MMT and plugging in modern catalytic converter configurations. That paper reports that the converter specification that achieves a highly efficient purification of the exhaust gas - namely, a close-coupled layout exposed to high temperature exhaust gas and a high cell-density configuration - is prone to plugging due to the presence of MMT, which in turn will seriously compromise its effectiveness. As Asian countries begin to introduce more stringent emissions limitations, and as automakers employ modern technologies in Asian vehicles, the presence of MMT in Asian fuel will present an impediment to achieving compliant emission levels over the useful life of the vehicles.Several of Afton’s comments on the impact of MMT on engines and emission control systems are based on the fact that the on-board diagnostic systems did not indicate a problem with the catalysts. However, according to the European Automobile Manufacturers Association (ACEA), MMT can prevent the on-board diagnostic (OBD) systems from identifying the failed catalytic converter. ACEA states that the “presence of MMT in the system can cause a false reading by the OBD system, potentially allowing a failed catalyst to go unnoticed and unrepaired.” (ACEA Position on Metal Based Additives: A recent, August 2008, report prepared by Sierra Research, Inc. for the Canadian Vehicle Manufacturers’ Association and Association of International Automobile Manufacturers of Canada on “Impacts of MMT Use in Unleaded Gasoline on Engines, Emission Control Systems, and Emissions” (Report No. SR2008-08-01) reviewed the available studies and presented new information regarding the impact of MMT on vehicles with advanced emission control systems, such as those that were sold and continue to be sold in Canada in order to comply with the Tier 2 emission requirements. The report concludes with respect to the consequences of the use of MMT-containing fuels in vehicles that comply with the Tier 2 regulations: (1). Plugging of catalysts due to manganese oxides on in-use vehicles can occur and has been documented at this point to be a substantial problem on a number of different models of in-use Canadian vehicles produced by a number of different manufacturers, (2) Vehicles with catalysts plugged by manganese oxides can have driveability problems due to excessive exhaust system backpressure. These problems can be corrected only by catalyst replacement, (3) Vehicles with catalysts plugged to a substantial degree by manganese oxides will generally experience MIL(malfunction indicator light) illumination and have fault codes stored indicating catalyst failure. The MIL can be extinguished and fault codes prevented from being stored only if the catalyst is replaced, (4) The plugging of catalysts by manganese oxides is most frequently observed on vehicles with advanced emissions controls systems that incorporate HDCC (high cell density close-coupled) catalysts. Such vehicle designs are expected to become widespread as all new vehicles sold in the U.S. and Canada are required to comply with the requirements of the Tier 2/LEV II regulations, (5) Some advanced technology vehicles for which catalyst plugging due to MMT has been demonstrated have also been shown to have, to varying degrees, increased tailpipe emissions of volatile organic compounds (VOC), CO, and NOx. (6) The rates of Canadian catalyst warranty replacement where MMT-related plugging has been documented were significantly higher than the U.S. warranty rate for vehicles equipped with the same emissions control systems. The rate of increase in Canadian warranty rates slowed in direct response to the reduction in the use of MMT in Canadian gasoline, (7) There is no demonstrated method, other than eliminating MMT from the fuel, to ensure that an emission control system that allows a vehicle to comply with the requirements of the Tier 2/LEV II regulations will not experience catalyst plugging caused by manganese oxides as well as one or more of the observed problems of degraded driveability, MIL illumination, and increased emissions.
The report also evaluated the impact of MMT use on emissions from the Canadian vehicle fleet. It reached the following conclusions: (1) Using conservative assumptions that likely understate the impact of MMT use on emissions of in-use vehicles, it was estimated that reintroduction of MMT® in 2008 in Canada at historic levels would result in increases in VOC, CO, and NOx emissions of 77%, 51%, and 12%, respectively, by 2020; and (2) Despite the cessation of MMT use in Canada in 2004, the legacy of MMT use will be increases in VOC and CO emissions, as well as modest reductions in NOx emissions.

Modification to the Road Map
No modifications in the Road Map were made in this respect.
E. Balanced representation of the MMT issue
CommentsCAI present a more scientifically sound and balanced presentation of MMT ® and include Afton’s comments as part of the final Road Map and on CAI’s website.By providing a more balanced and complete body of information countries and individual fuel refiners will be better able to make appropriate fuel formulation decisions based on their own unique circumstances.For all of these reasons, the Road Map’s recommendation against use of MMT® is completely unwarranted. Afton Chemical requests that the recommendation against use of MMT® be removed from the Road Map and that Road Map be revised to present a more scientifically sound and balanced presentation of data pertaining to MMT®. Decisions regarding the composition of cleaner burning fuels should be made on a case-by-case basis after review of all of the relevant scientific data concerning the different fuel components that can be used to produce the cleaner burning fuel.Afton respectfully requests that CAI remove the sentence that recommends that Asian countries not use MMT ® (page viii of the Executive Summary).Responses:The Road Map is balanced in the manner it has addressed the issue of the use of octane enhancing additives. This is reflected by the commenting process on the Road Map in which no comments were received questioning the recommendation not to use metallic additives such as MMT from either global and national oil companies, vehicle industry or additive companies other than Afton. Feedback received following the posting of the first consultation draft in May 2006 and following the circulation of the 2nd Consultation Draft in December 2007 indicated support for the position taken and analysis provided on the issue of octane enhancing additives. The carefully constructed recommendations on the use of Metallic additives have broad support from all other parties. Main affected sectors such as the oil -, vehicle - and the emission control devices industries have indicated in public comments that the Road Map is a balanced study.Afton commented that decisions regarding the composition of cleaner burning fuels should be made on a case-by-case basis after the review of all relevant scientific data. The Road Map clearly acknowledges the need for countries to customize the Road Map to their own circumstances (para. 423, Road Map,). However, this should however not lead to a situation in which each country in Asia conducts its own extensive research on the impacts of specific fuel parameters and additives prior to decision and rule making. Asian countries do not have the capacity to conduct the extensive risk assessment studies which the USEPA is requiring Afton to conduct. With respect to the use of metallic octane enhancing additives, the Road Map applies the principle that countries should take their own unique situation into consideration and that in specific cases individual countries may choose to allow the use of metallic additives: “If Asian countries do decide to authorize the use of MMT, ferrocene, or other ash forming metal based additives to raise octane, they should do so on a refinery-by-refinery permit basis, with clear deadlines for phasing out of the use of these additives while ensuring that they are used in limited concentrations. The decision on the use of metallic additives should be taken by regulators and should not be left to individual refiners” (para. 443, Road Map). It is correct, as stated in para. 251 of the Road Map, and agreed to by Afton, that consideration of the health effects of additives requires consideration of several factors, including the degree to which use of the additive(i) increases exposure to components of the additive itself or to combustion byproducts of the additive (e.g., the metal based additives or MTBE), and the toxicity of those substances at ambient levels;(ii) decreases or increases vehicle emissions, which can improve or worsen ambient air pollution (e.g., a change in the emission of precursors of ozone, or a change in certain air toxics); and(iii) reduces the content of other components of gasoline that are known to have adverse health effects.We argue that this approach has been followed. The Road Map identifies several components of existing fuel as of concern (e.g. benzene) and then carefully reviews the implications of better refining processes and of all additives for emissions and health effects both of those compounds and of others that might cause health effects. Given this background, the Road Map concludes that The number one strategy for reducing exposure to the problematic compounds in existing fuels is not using additives at all but rather revamping refinery capacity to make cleaner fuel. o Following that, the Road Map reviews each of the additives and concludes, based on the health evidence, and the conclusions of world regulatory bodies for all of the major potential additives – the oxygenates and metallic compounds – that the oxygenates, while not without some problems such as causing odor in water supplies, have not shown the inherent toxicity shown with some of the metallic compounds, especially manganese and MMT. Thus the Road Map in a balanced review determined that as a transitional approach, the use of oxygenates – done with caution – could be supported, but urged the use of the precautionary principle when considering the metallic additives.
The position taken in the Road Map with respect to additives reflects the on the ground situation in most parts of the fuel markets. The first option in ensuring an adequate octane level is changes in refining technology. If this can not be achieved, additives can be considered. In deciding on what type of additives to use two considerations need to be made: what are the health impacts and what are the impacts on the engine emissions. The recommendations in the Road Map are balanced and carefully follow this line of argument.
Additive type Health impacts Engine/emission technology impact Oxygenates In USA MTBE seen as an environmental nuisance and therefore banned, in Europe not seen as a health risk after major exposure studies No impacts and no concerns expressed by vehicle industry and emission control device industry at levels recommended or legislated by regulators Metallic Acute health risks by direct ingestion, still topic on ongoing regulatory exposure assessment in the USA Serious concerns about impacts on emission control devices vehicle industry and emission control device industry at any level.
Modification to the Road MapThe Road Map emphasizes that the use of metallic additives is a topic that should be covered by regulation and that decision making on this can not be left to individual refiners (para. 443, Road Map).
The current concluding chapter deals with octane enhancing additives on a point by point basis in terms of impact on health and emissions for the different classes of additives. An additional paragraph will be inserted which ties the arguments together so that the recommendation to apply the precautionary principle is explained in a more comprehensive manner taking into the account the criteria for its application in the Rio Declaration (para. 442, Road Map).
F. Application of the precautionary principle.Comments:Because of the multi-dimensional nature of the risks posed by motor vehicle fuel combustion, any application of precaution to deal with those risks must also be multi-dimensional to be effective. This is confirmed by recent guidance issued by the Government of Canada relating to the application of “precaution” in scientific decision making. The Canadian guidance highlights the critical importance of “comparative” assessments whenever trade-offs must be made. Precautionary measures should be cost-effective, with the goal of generating (i) an overall net benefit for society at least cost, and (ii) efficiency in the choice of measures . . . Consideration of risk-risk tradeoffs or comparative assessments of different risk would generally be appropriate . . . The adoption of a precautionary approach to any single component of gasoline without proper consideration of the multi-dimensional nature of the risks posed by gasoline combustion may have the unintended result of increasing overall risks to public health or welfare. Yet that is precisely what the Road Map proposes when it invokes the precautionary principle in the case of octane-enhancing metallic additives, such as MMT®. For these metallic additives, the Road Map fails to acknowledge, much less address, the inevitable trade-offs that must be made when evaluating the comparative risks and benefits of different fuel formulations. Instead, the Road Map focuses exclusively on potential risks of metallic additives and simplistically recommends that metallic additives not be used “until and unless the scientific and health studies show that they are safe.”
Because gasoline has inherent risk no matter how constituted, the simplistic, one-dimensional application of the precautionary principle to a single component of gasoline, such as MMT ®, without considering how removal of the single component will impact other components of gasoline cannot ensure the avoidance of serious risks to public health which is the very essence of the precautionary principle. In fact, it may do just the opposite. As one government health authority recently observed with respect to potential problems of alternatives to MMT®:This situation highlights the difficulty and necessity of assessing the advantages and disadvantages of any alternative, and the caution with which the introduction of any alternative must be approached. It should be noted that the amount of scientific information on the neurotoxicity of an exposure to manganese is substantial compared to the equivalent information on the toxicity and potential exposures associated with some of the alternatives. 2. Responses:The recommendation to apply the precautionary principle for metallic additives in Asia is fully in line with the concept of the precautionary principle as defined in the Rio Declaration and proposes policy for Asia which in the developed countries already exists formally or on the basis of voluntary action on the side of the oil industry.The precautionary principle as proposed in the Road Map Document is based on the original interpretation as provided in the Rio Declaration on Environment and Development (Principle 15), which states: “In order to protect the environment, the precautionary approach shall be widely used by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”The recommendation to apply the precautionary principle for the use of metallic additives was arrived at based on the following arguments:Threat of serious or irreversible damage. There is growing concern on the negative impact on the (chronic) health effects of metallic additives as evidenced by a growing body of scientific literature. . The body of evidence on the harmful impact of metallic additives on the performance of catalysts and on board diagnostic systems is growing and points at serious harm in terms of exposing the general population to harmful emissions.Lack of full scientific evidence: Additional studies on the health impacts of metallic additives are ongoing, such as the testing in the United States required by U.S. EPA. In the case of the US, the present situation in which less than 1% of fuel contains very low levels of MMT, and the fact that MMT is undergoing testing, have created a situation where there is no immediate need to take action - such as the application of the precautionary principle - and that results of the ongoing studies can be awaited before formal rule making is considered. In Canada, where additional studies were planned, refiners have voluntarily stopped the use of MMT, lessening the need for such additional studies. Following the phase out of leaded gasoline in Asia fuel quality regulators are actively considering their policies on the use of octane enhancing additives and are exposed to lobbying by the retailers of both metallic additives and oxygenates, yet the capacity to implement detailed risk assessment studies to assess health exposures and the impact on vehicle emission control systems is much more limited in these countries, and the scientific evidence from the developed world is not conclusive.Postponing cost-effective actions. (a) As clearly explained in the Road Map the precautionary principle does not apply to MMT only but to all metallic based additives. (b) The Road Map explains that alternatives are available to refiners that can be used to produce gasoline with sufficiently high octane levels. High quality gasoline has been attained across the world using a combination of refinery configurations, refining processes and oxygenates additives. (c) A large majority of countries, both developing countries and especially developed countries, have achieved high-quality gasoline without the use of metallic additives, through these methods. In none of these cases has the use of other methods of achieving higher octane gasoline resulted in price increases in gasoline beyond the carrying capacity of the market. It is unlikely that the costs of producing the fuels without metallic additives are larger than the economic benefits of prevented negative impacts. Prevention. The use of the precautionary principle is especially relevant for the case of Asia where the rapid motorization is resulting in increased demand for gasoline. After a number of years of stagnation in the creation of new refining capacity, in recent years there has been a strong increase in the expansion of existing refineries and the construction of new refining capacity. It is important that Asian regulators are fully aware that the construction of new refining capacity minimizes the need for the use of octane enhancing additives, especially metallic based additives.
This means that all requirements, as set out in the Rio Declaration, for the application of the precautionary principle, have been met in the recommendation in the Road Map on the use of the precautionary principle for the use of metallic additives in Asia.
The recommendation to apply the precautionary principle can not be equated with calling for a ban on the use of MMT since the Road Map allows for countries to use MMT or other metallic based additives on a selective basis if there are specific, urgent considerations which merit this. However, in line with the analysis and recommendations this should be on a refinery-by-refinery permit basis, with clear deadlines for the phase out of the use of MMT, ferrocene or other ash forming metal based additives while ensuring that they are used in limited concentrations” The recommendation to apply the precautionary principle to the use of metallic additives in Asia does not present a new direction in policy making on regulation of fuel additives. Internationally, there has been a clear acknowledgement of the potential risks of the use of metallic additives in both developed and developing countries. In some cases this has resulted in banning the use of MMT, as in the case of California, India, or is being considered, as in the case of the EU draft fuel quality regulation. In cases where no comprehensive formal bans exist, the use of MMT has been very limited because of voluntary restrictions on the use by refiners and fuel distributors.The current state of environmental protection enforcement and fuel quality regulation in Asian countries is substantially below that applied in Europe, North America, and Australia. As a result, there is no assurance that requirements to limit use of MMT in Asian fuels will be adhered to, raising the very real possibility that higher levels will be used, and that public exposures may be substantial. Such exposures may be higher than levels anticipated by health agencies in developed countries when they concluded that public health risk may not be significant.Concerning the situation in Canada, the Canadian government’s position on the use of MMT has been influenced by legal action against the Canadian government under the NAFTA Free Trade Agreement. However, while the government initially called for additional health impact and risk assessment studies it appears that the market in Canada has implemented the recommendation of Afton and “assessed the advantages and disadvantages of any alternative, and the caution with which the introduction of any alternative must be approached”. Since 2005 no MMT has been added to gasoline in Canada. This has resulted from internal dialogues between the vehicle manufacturers and oil refiners in Canada. 3. Modification of the Road Map
As indicated above the Road Map emphasizes that the use of metallic additives is a topic that should be covered by regulation and that decision making on this can not be left to individual refiners. Also, the current concluding chapter which now deals with octane enhancing additives on a point by point basis in terms of impact on health and emissions for the different classes of additives will be modified with an additional paragraph, as explained above, that will tie the arguments together so that the recommendation to apply the precautionary principle is explained in a more comprehensive manner taking into the account the criteria for its application in the Rio Declaration.