Beehler was "the big boss" who met with the White House and the EPA on the perchlorate issue, according to the deposition of an Air Force colonel in a lawsuit filed by the Natural Resources Defense Council.
Beehler said he "had absolutely no influence."
Beehler angered the Senate environment committee when he wasn't able to produce records or minutes of his staff's frequent meetings with manufacturers and users of perchlorate.
That shows he is "not qualified to be inspector general," Boxer said.
Beehler has told committee investigators that he will recuse himself from any EPA deliberations on 18 chemicals, including perchlorate, on a Pentagon list of contaminants that might be regulated.
He said in an interview that he would also recuse himself from "anything that has to do with Koch."
Dudley headed a free-market think tank -- the Mercatus Center at George Mason University -- that is supported in part by Koch Industries, whose chairman sits on the board.