A Senate committee has approved President Trump’s nominees for four key U.S. Environmental Protection Agency posts as well as his choice to lead the Federal Highway Administration, but the panel’s senior Democrat is vowing to fight at least one of those EPA picks—Michael Dourson, Trump’s selection to head EPA’s office of chemical safety and pollution prevention.

The closest calls at the Environment and Public Works Committee’s Oct. 25 meeting were 11-10, party-line votes to approve Dourson and attorney William Wehrum, Trump’s nominee to lead EPA’s office of air and radiation. [View webcast of meeting here.]

The other nominees all were cleared by voice vote.

The next step for all of them is Senate floor action. But the narrow margins for Dourson and Wehrum may signal that some Democrats will use procedural tactics to try to slow those nominations’ paths through the floor.  An official at a major environmental group expects more than one senator to take such action.

Dourson appears to face the strongest opposition among the committee’s Democrats, judging from their highly critical comments at the hearing. The panel’s top Democrat, Tom Carper (Del.), said, “On the nomination of Michael Dourson, we will never give up in opposition to it.”

Committee Chairman John Barrasso (R-Wyo.) supported all of the nominees, including those for EPA positions, saying they “have proven themselves to be well-qualified, experienced and dedicated public servants.” He urged that they be approved.

Carper and other Democrats recalled that Congress last year passed a Toxic Substances Control Act update that was the product of bipartisan work. But he contended that Dourson’s nomination “makes a mockery” of the process that led to that legislation, which the chemical-safety office is charged with implementing. [Read Carper's prepared statement here.]

Dourson is the founder and former president of Toxicology Excellence for Risk Assessment, a nonprofit research organization. In 2015 that entity became part of the University of Cincinnati College of Medicine’s department of environmental health.

In a statement at his Oct. 4 confirmation hearing before the same Senate committee, Dourson said that, if approved, “I will dedicate my mind, body and spirit to the work of this [EPA] office, to working with its staff, to the protection of the American public and its environment from overexposure to pesticides and chemicals….”

But Carper contended that Dourson, in much of his career, “essentially sold his science to the highest bidder and recommended standards for toxic chemicals that were tens, hundreds, sometimes even thousands of times less protective than EPA’s own standards.”

Sen. Ben Cardin (D-Md.) said that If Dourson were approved for the EPA chemical-safety post, it would amount to “putting the fox in the hen house.” Sen. Sheldon Whitehouse (D-R.I.) said the vote on Dourson “breaches the faith” of the process leading to the toxic substances law.

The Senate committee approved the other four nominees on voice votes, including former Iowa Dept. of Transportation Director Paul Trombino, Trump’s choice to be FHWA Administrator; David Ross, for EPA assistant administrator for water; and Matthew Leopold, for EPA general counsel.

Ross is director of the Wisconsin Dept. of Justice’s environmental protection unit. Leopold, an attorney in Tallahassee with the law firm of Carlton Fields, previously was the Florida Dept. of Environmental Protection’s general counsel.

Jeffrey Baran also was approved by voice vote to continue as a member of the Nuclear Regulatory Commission. Baran’s current term is up on June 30, 2018.