WASHINGTON — A bill passed through a House committee Wednesday would bolster safety measures for coal miners and add new rules for retreat mining at depths of more than 1,500 feet underground.

But critics say some of the provisions in the bill are already in place under current law, and some of the new safety rules proposed in the bill could harm Utah mining companies.

The danger of retreat mining is one of the factors being considered in the investigation into the Crandall Canyon Mine accident. Six miners who had been working about 1,500 feet underground in the mine were trapped in the August collapse, and their bodies haven't been recovered. Three rescuers died days later in another collapse.

Retreat mining involves excavating coal from an underground chamber while leaving behind pillars of material for support. Once the deposit is depleted, miners remove the pillars and "retreat" back toward the mine's entrance.

The technique was being used at Crandall Canyon. Initial reports of the collapse at the mine gave the appearance the collapse could have been caused by earthquake activity. Scientists later concluded pressure on the pillars within the mine caused portions of the pillars to burst.

U.S. Rep. George Miller, D-Calif., introduced his mine safety bill just weeks before the accident, with the aim of building on a mine-safety law passed last year that he believed did not go far enough in reforming safety rules to protect miners.

With a 26-18 vote, the House Education and Labor Committee on Wednesday passed Miller's Supplemental Mine Improvement and New Emergency Response Act, known as the S-MINER bill, which will send it to the House floor. Rep. Rob Bishop, R-Utah, who sits on the committee, voted against the bill.

"It's hard to find something positive about this thing," Bishop said after the vote.

Bishop said the original MINER Act, passed 2006 in wake of the Sago Mine disaster, needs time to be fully implemented before Congress should act to change it. He said some of the provisions in Miller's bill are already in place, and some of the bill's proposed new safety rules could harm Utah's mining industry.

One provision in the bill would put stricter rules on conveyor belts used to bring coal out of mines, forcing mines to get rid of old belts after five years and requiring new belts to use the latest technology. Bishop said belt mining is used more in Western states than in Eastern mines, so Utah mining companies would face a financial disadvantage.

Miller's bill also puts a full-time position at the Mine Safety and Health Administration to deal with communicating with the media and families after an accident.