Less than a month after the latest mining tragedy — and just over a year after Congress changed safety laws after earlier disasters — a decidedly less friendly Congress will question administration and industry officials about further changes.

Richard E. Stickler, director of the Mine Safety and Health Administration (MSHA) — a recess appointment on whose nomination Senate Appropriations Chairman Robert C. Byrd, D-W.Va., still has a hold — is slated to testify Wednesday before the Labor, Health and Human Services and Education Appropriations Subcommittee regarding the Aug. 6 cave-in at the Crandall Canyon coal mine in Utah. That accident trapped six workers, who are presumed dead. Three rescue workers were killed in a separate collapse Aug. 16.

Mining industry officials insist that more regulations are not necessary, and say they are still reeling from last year’s changes.

“We have a full plate now,” said Luke Popovich, a spokesman for the National Mining Association. “It would not be helpful, we don’t think, to add further requirements to the law.”

Last year’s changes were enacted after an explosion in West Virginia’s Sago Mine killed 12 workers in January 2006. They included requirements to install wireless communications equipment and tracking devices within three years. They also raised maximum fines for accidents and gave the government the power to shut down mines when operators don’t pay fines.

House Education and Labor Chairman George Miller, D-Calif., complained last year that the changes did not go far enough, and he and Senate Health, Education, Labor and Pensions Chairman Edward M. Kennedy, D-Mass., introduced bills in June (HR 2768, HR 2769, S 1655) that would do more.

The bills would shorten to 15 months the deadline by which mines have to install new communication equipment, increase MSHA’s authority and increase penalties for mines that have a “pattern of violations” or that retaliate against miners who report safety or health violations.

Miller and Kennedy have requested more information from the Labor Department on the incident at the Crandall Canyon mine, and they both plan to hold hearings on the disaster and their bills in early October. The hearings are intended to spur action on the bills, but for Byrd, they also will be an important test for whether he will maintain his hold on Stickler’s nomination when his recess appointment expires in January.

“We’re just hoping to get some movement on this and get to the bottom of what happened in Utah,” said Byrd spokeswoman Jenny Thalheimer. “But this is also an opportunity to see how willing Richard Stickler will be to make some changes with MSHA or if he’s really going to be out there advocating for the miners.”