Wednesday debate on the bill was marked by Democratic arguments that the bill would weaken air quality standards across the country. The bill would prevent the EPA from regulating emissions from vessels that service offshore drilling operations, a change that Democrats said prevents EPA regulation on what can be the predominant source of emissions.

Democrats worked to attack this provision and others in the bill, but all 10 Democratic amendments were turned away.

Republicans acknowledged during the debate that the bill would help Shell obtain an exploratory permit off Alaska's shore.