Near the end of the Tuesday session in Washington, the Georgia Republican lit into Graham H. Graham, Imperial's vice president of operations.
"I believe Chambliss was espousing the company line in an effort to discredit and blunt Mr. Graham's testimony," the attorney, Philip Hilder, said Wednesday.
Mr. Chambliss denied that, saying he spoke on behalf of the families of the 13 people killed as a result of the Feb. 7 explosions and fire at the Port Wentworth refinery.
Mr. Graham testified about what he said were dangerous conditions he saw there.
Imperial faces proposed fines of $8.8 million, multi-pronged federal investigations and possible criminal prosecution. The proposed fines stem from 200-plus alleged safety violations at Port Wentworth and at Imperial's refinery at Gramercy, La.
Mr. Graham also said he was told by senior executives he was being overzealous in his efforts to make the plant safer.
Near the end of the hearing, Mr. Chambliss questioned Mr. Graham aggressively. He twice said he doubted Mr. Graham's sincerity and cut him off before he could answer a final question.
But U.S. Sen. Patty Murray, D-Wash., who led the panel -- the subcommittee on employment and workplace safety -- let Mr. Graham answer.
Mr. Chambliss is not a member of the subcommittee. He was invited as a courtesy because he is a Georgia senator, said subcommittee spokesman Matt McAlvanah.
Johnny Isakson, Georgia's other senator, is the top-ranked GOP member.
Mr. Hilder said he thinks Imperial suggested questions for Mr. Chambliss to ask Mr. Graham and accused the senator of a "cheap shot" against his client.
"He's more interested in discrediting Mr. Graham than discovering the facts, and I think he's the one who's being insincere," Mr. Hilder said.
Mr. Chambliss rejected Mr. Hilder's claims.
"I ask my own questions," the senator said. "That's what lawyers are paid to say."
He did say Imperial suggested questions to senators to ask Edwin Foulke Jr. Mr. Foulke, the head of the U.S. Occupational Safety and Health Administration, also testified Tuesday.
"I never saw them," Mr. Chambliss said of the questions.
Imperial spokesman Steve Behm said the company suggested questions to subcommittee members, but none to Mr. Chambliss for Mr. Graham.
Mr. Chambliss, who received a $1,000 campaign donation in June from Imperial's political action committee, did say he was "infuriated" at Mr. Graham.