The Oxygenated Fuels Mandate
The Hidden Safety Issue
Dr. Robert R. Swank Jr.
October 12, 2004
Unintended consequences are
a constant reminder to policy-makers that however well-intended
their schemes might be, something almost always gets overlooked.
A case in point is an ambitious plan to provide for cleaner air
in urban areas -- one embraced by Congress, the White House, and
the US Environmental Protection Agency (EPA) over a decade ago --
that has now come back to haunt the American driving public.
Using the best science available to
it at the time, EPA in the late 1980s concluded that any of several
candidate gasoline additives containing oxygen (i.e., oxygenates),
such as ethanol or ethers, could be effective in reducing tailpipe
emissions of carbon monoxide (CO), hydrocarbons, and particulates.
Indeed, model projections indicated that oxygenate use could bring
many urban areas back into compliance with federal CO standards
during the winter months, and help reduce summer urban smog and
ozone problems as well. The US Congress reviewed and accepted EPA's
findings and incorporated a fuel oxygenate requirement (approximately
2 to 3 percent by weight of oxygen) in the Clean Air Act amendments
(CAA) of 1990.
With the oxygenate mandate in place,
two candidates quickly emerged as the favorites to help provide
American cities with cleaner air. The refining industry gave the
nod to methyl tertiary butyl ether (MTBE), which could be profitably
produced from certain waste parts of crude oil. Congress, on the
other hand, by subsidizing the production of corn-based ethanol,
smoothed the way for this oxygenate. Its supporters argued that
ethanol, as a renewable resource, contributes to US energy independence
and that its use also benefits American farmers.
The oxygenate mandate went into effect
in 1995, and problems immediately surfaced. As early as 1987 and
again in 1993, EPA scientists had warned that MTBE-blended fuel,
when spilled or leaked, could contaminate ground and surface water
in those areas of the country where it was in widespread use. And
this is exactly what happened. Such was the uproar in communities
affected by this contamination that EPA was eventually forced to
ask Congress to phase out the use of MTBE. EPA's failure to heed
the warnings of its own scientists on the use of MTBE, or to notify
Congress of the potential problems with this oxygenate, is deeply
troubling and underscores the need for substantial changes in the
way the agency conducts its affairs. The fact that there is neither
a scientifically defensible environmental assessment nor human health
exposure-risk profile for what is arguably a better alternative
to MTBE, ethyl tertiary butyl ether (ETBE), even though ETBE has
been in use for almost a decade in the US and Europe, further underscores
the need for improved procedures at EPA.
Even more serious is a safety issue
that has arisen since the oxygenate mandate went into affect. Refueling
fires at gas stations in the US have increased dramatically since
1995. Research conducted by the Petroleum Equipment Institute, American
Petroleum Institute, and Fowler Associates, a South Carolina-based
testing, training, and consulting firm, shows that the fires occur
most frequently during the fall, winter, and spring when cooler,
dryer air promotes the generation of static charges on people. Here's
what can happen. When a customer pulls into a gas station on a cold,
dry day, he gets out of the car and goes to the pump, inserts the
fueling nozzle, and locks it on automatic. To escape the cold, he
gets back into his car. After the nozzle clicks off, the customer
gets out of the car and heads for the gas tank. Not realizing that
a vapor cloud of volatile organic compounds (VOCs) from the fuel
has formed around the nozzle and the filler opening of the vehicle,
he reaches for the nozzle through the vapor cloud and his statically-charged
body discharges its accumulated voltage via a spark. The result
too often is a flash flame and a fire that maims or kills, and destroys
vehicles and even gas stations. This scenario becomes more probable
under the pressure of federal CAFE standards on the automobile producers.
To meet the required mileage standards, manufacturers reduce vehicle
weight by using more plastics and other insulating materials, including
in the interiors, thereby elevating the possibility of significant
static charge generation on the occupants. The National Highway
Traffic Safety (NHTSA) Administration’s recent proposal to raise
CAFÉ standards for “light trucks” – SUVs, minivans, and pickups
– will force manufacturers to make additional weight reductions
in these vehicles. If NHTSA’s proposal is allowed to stand, it will
only contribute to the problem of refueling fires and will thus
undermine NHTSA’s mission of providing for automotive safety.
To date, Fowler Associates has documented
many such fires since the mid-1990s. Steve Fowler, the firm's president,
strongly suspects this is but the tip of the iceberg because many
incidents go unreported, or are lumped into the general category
of "vehicle fires."
The growing number of refueling fires,
like the MTBE water contamination problem, is another unintended
consequence of the Clean Air Act amendments of 1990 and its mandated
use of oxygenated fuels, especially gasoline and alcohol blends.
Refiners blend these fuels for season-to-season use, and for distribution
both in areas in compliance with federal air-quality standards as
well as in areas with non-attainment status. During the summer,
one major control on the volatility of the fuel is its Reid Vapor
Pressure (RVP), which is capped to keep the fuel's VOCs to a minimum.
Since ethanol increases fuel volatility when blended with gasoline,
as compared to ETBE that significantly lowers it, the summer RVP
cap can only be achieved in ethanol blends by removing volatile
components from the gasoline itself via an extra, costly refining
step. Nevertheless, the cap does help reduce volatile hydrocarbon
emissions in urban areas and lowers the risk of summer refueling
fires at the gas pump.
In contrast, during cooler seasons,
refiners typically raise the RVP of fuel by increasing the levels
of pentane and butane in the refined gasoline. This leads to better
combustion performance in the fall, winter, and spring months. However,
when ethanol is added to these fuels, the resultant RVP is much
higher, perhaps too high. These very high, uncapped “winter” RVPs
result in greatly increased amounts of VOCs escaping fuel tanks
at the very time when static-spark formation potential is at its
highest, thereby significantly elevating the risk of refueling fires.
What can be done to prevent the spreading
of refueling fires? "We can begin by capping and reducing the
fall, winter, and spring RVPs of blended fuels that would significantly
cut the amount of escaping VOCs and thus lower the risk of refueling
fires in cooler weather," says Mike Colburn, a California-based,
independent fuel researcher who has spent years studying the issue.
Furthermore, Colburn notes that there
is ample research showing how ethanol-blended fuels permeate and
can reduce the effectiveness of elastomer components in today's
state-of-the-art fuel supply and delivery systems. This poses an
added potential safety hazard because fuel injection systems require
high pressures and volumes to work properly.
Fixing this system that is definitely
broken will require a thorough review of the whole issue of fuel
formulation, including formulation effects on modern fuel systems
and the associated risks of refueling and collision-related fires.
This effort should involve all the key stakeholders, including the
auto industry, the oil industry, EPA, and the Departments of Energy
and Transportation. Up to the present, it appears that the automotive
industry hasn’t always been recognized as a stakeholder in the issue
of fuel formulation. That needs to change. The entire effort will
likely entail reopening and reforming the Clean Air Act using updated
science and common sense.
Moreover, in light of the problems
that have resulted from the use of MTBE and ethanol, it is time
to consider alternative oxygenates. Based on its properties, a prime
candidate is ETBE. ETBE has about one-third the solubility of MTBE
and, thus, represents a greatly reduced threat to groundwater in
the event of blended fuel spills or leaks. In addition, ETBE is
reported to provide twice the increase in octane rating and significantly
greater reductions in tailpipe emissions of VOCs, nitrogen oxides,
and carbon monoxide than ethanol. Furthermore, the reduced volatility
of ETBE-gasoline blends is suitable for year-round use without costly
gasoline refining adjustments for summertime weather, and represents
a greatly reduced year-round potential of fire hazards associated
with refueling and crashes.
And, because it's produced using ethanol,
ETBE would also continue to benefit corn growers. In addition, converting
ethanol to ETBE can be done at refineries using virtually the same
equipment now used to make MTBE. This would preserve capital and
keep the refining industry active in producing oxygenates. Moreover,
blending at the refinery would save transportation costs and reduce
overall environmental threats.
Of course, ETBE or any other alternative
oxygenate should undergo strenuous testing and assessment to ensure
that the unintended consequences that have followed in the wake
of MTBE and ethanol are not repeated. Our collective failure to
carry out such a comprehensive review when the 1990 CAA amendments
were enacted has cost us dearly. It's time to take corrective action.
Robert R. Swank Jr., Ph. D., was
a senior researcher and research manager over a 28-year career at
the US Environmental Protection Agency.