Two Democratic senators suggested Thursday they may block one or more of President Bush's nominees to key Environmental Protection Agency (search) posts unless they get answers they want from the agency.

Sen. Barack Obama, D-Ill., said he wanted to know when the EPA would issue regulations for lead paint (search) exposure from house remodeling.

"I'm not interested in holding any of your nominations hostage," Obama said at a Senate Environment and Public Works Committee hearing on nominees for EPA deputy administrator and to head the agency's enforcement and solid waste divisions.

"But if you get any resistance from your future boss, the administrator, about this, you should let him know I'm deeply concerned about this and willing to gum up the works a little bit until I get a clear response," he told the nominees.

Obama told reporters after the hearing that he wanted a definite date from EPA officials about when they would issue the regulations, which by law were supposed to have come out in 1996. If that's not forthcoming, he said, he would use "whatever mechanisms I have available to get their attention."

Sen. Barbara Boxer, D-Calif., indicated she might block one of the nominees unless she gets details on an EPA list of 103 Superfund sites where the agency has suggested human exposure is possible. She said she wants the sites listed in order of health hazard, along with details on cleanup costs and how many children live nearby.

"All I've gotten from EPA is incomplete information," Boxer told Susan Bodine (search), the nominee for assistant administrator for the office of solid waste and emergency response, which includes the Superfund program.

Senate procedures allow any senator to block a nomination.

Also getting a hearing Thursday were Marcus Peacock (search), tapped to be EPA deputy administrator, and Granta Nakayama (search), nominated for assistant administrator for enforcement and compliance.

Bodine and the others noted that since they aren't yet in the EPA they have little control over how the agency releases information, but they promised to work with the senators.

Nakayama faced criticism from Sen. Max Baucus, D-Mont., over his law firm's representation of W.R. Grace and Co., which is facing criminal charges over asbestos contamination from a mine in Libby, Mont. Nakayama said he had no involvement in Kirkland & Ellis' work for W.R. Grace.