Higher polluting VOC emissions allowed to keep petrol prices down

The US Environmental Protection Agency (EPA) has permitted an increase in vehicle emissions of smog-producing volatile organic compounds (VOCs) in order to keep petrol prices down.


EPA Administrator Christie Whitman has announced the move which only applies to Chicago and Milwaukee, the two US cities that use ethanol exclusively in reformulated petrol to avoid price hikes such as last summer when petrol costs hit $2.75 per gallon. Whitman said that adjusting the rule will make it less expensive to blend ethanol into reformulated petrol, which is blended with oxygenates to produce a cleaner burning fuel, reducing VOCs and toxic emissions.

Reformulated petrol is required by law in cities with high levels of smog over the summer months when it presents the greatest risks to health, and in Midwestern cities ethanol is favoured over methyl tertiary butyl ether (MTBE).

“I recently directed EPA staff to finalise an upward adjustment to the VOC standard,” Whitman said. “Based on preliminary data, we believe we will be able to adjust the standard closer to 0.3 pounds per square inch Reid vapour pressure (a measure of how quickly fuel evaporates) which will provide greater flexibility than the 0.2 pounds that was originally proposed.”

When added to petrol, ethanol increases the evaporation rate, causing more VOC emissions, but reducing carbon monoxide (CO) emissions, both of which play a role in ozone formation. While there will be an increase in VOCs they will be offset by the concurrent CO reductions, Whitman said, adding that air quality will not be compromised by the change. The cities will receive credit toward their carbon monoxide reductions associated with ethanol formulated gasoline.

The EPA has also been meeting with Midwest refiners over the past two weeks to evaluate problems they experienced last year with swapping fuels in tanks to provide cleaner summer fuel for the ozone (smog) season. “We don’t expect any problems this year and we will be monitoring the situation closely,” said Whitman. “If individual companies experience unforeseen difficulties, we will provide flexibility to ease the transition to summer blends.”

“I am very concerned about the potential for price increases caused by many different factors such as increased demand and pipeline disruptions,” Whitman said, justifying the move.

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