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MTBE: Harmful additive |
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MTBE, a gasoline additive,
was at the center of the energy reform debate in the United States.
Opposition groups conditioned the bill´s approval in the Senate
to the repeal of a provision that protected the producers of MTBE
from lawsuits arising from contamination.
In this section we explain the controversial MTBE.
1. What is MTBE?
- Methyl Tertiary Butyl Ether (MTBE) is a chemical substance used
to oxygenize gasoline.
2. What is the purpose of adding MTBE
to gasoline?
- The goal is to promote complete combustion and reduce the level
of carbon monoxide emissions from automobiles.
3. How long has it been in use?
- MTBE has been used in gasoline in the United States since the
1970s as a replacement for lead, primarily to increase octane rating
or the gasoline’s resistance to igniting or beginning the
combustion process before the moment of maximum compression. Since
1992, it has been used in several US states to satisfy a Federal
Clean Air Act requirement that oxygen be added to the gasoline in
areas where carbon monoxide levels are high.
4. What are the environmental consequences
of MTBE use?
- One of the consequences of MTBE use is seepage into the ground.
MTBE is highly water soluble and therefore difficult to contain
or control once it has come in contact with water. It has been found
that if you store MTBE in underground tanks it can seep for months
or years into the water table contaminating potable water sources.
5. Is MTBE harmful to human health?
- Although it has not been proven that water contaminated with MTBE
is harmful to human health, the US’ Environmental Protection
Agency has added MTBE to its List of Potable Water Contaminants.
Additionally it has been determined that MTBE is potentially carcinogenic,
based on tests done on rats exposed to high levels of the chemical.
Potable water that contains MTBE, even at low levels, acquire an
unpleasant taste and smell similar to turpentine, that renders it
undrinkable.
6. Is MTBE use banned?
- Yes, 27 US states have begun steps to ban or reduce the use of
MTBE in gasoline.
7. Are there alternatives to MTBE?
- Yes, ethanol, derived from corn, can be combined with gasoline.
However, there are studies which show that the change from MTBE
to ethanol could prove very costly, less efficient and more harmful
to the environment because of the quantity of subsidies and pesticides
which corn cultivation demands.
Sources:
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