United Mine Workers of America members testified at a Mine Safety and Health Administration hearing Monday in Grand Junction that changes being proposed in mine safety regulations would weaken standards.

The federal agency held the fifth of six nationwide hearings on the proposed changes, which haven't drawn much praise from either the miners union or many coal-mine operators."These laws are nothing but setting off a cannon to kill people," said Lester Walls Sr., a miner at the Wilberg, Utah, mine where 27 people were killed in December 1984. The victims included Walls' son, Lester Jr.

The UMW has long contended the MSHA-approved, two-entry system, which was in use at the Wilberg, leaves miners only two designated escapeways and provides inadequate ventilation.

The UMW also contended that MSHA inspectors wrongly granted a waiver allowing mining to continue in an area of the Wilberg despite a cave-in in a third passage which, although not a designated escapeway, might have provided a way out.

In May MSHA reissued 41 citations with fines totaling an industry-record $110,000 against the mine's owner, Utah Power & Light Co.

"I don't want any change. I want them to enforce what they've got now," Walls said. "If they had done what they were supposed to do, people would have walked away from that disaster."

Frank Stevenson, a member of the UMWA's international executive board, was one of 50 union speakers urging no change in the mining regulations.

"Don't put production ahead of mine safety, or the blood spilled on the coal will be on your hands," Stevenson said.

Steve Norman, a UMWA member from Illinois, said the new proposals would "be destroying a fine set of guidelines" under which mine operators and miners have made good progress in making the mines safer.

John Reeves, president of Mid-Continent Resources Inc., a Glenwood Springs, Colo., coal mining company, disagrees with the new regulations, too.

"We think they're taking our ability to manage the mine away from us," he said. MSHA proposes making better use of development technology, such as using more electronic sensing devices to pick up the presence of deadly methane gas inside coal mines.

Called an AMS system, it evaluates oxygen, carbon monoxide and methane levels and can give early warning of fire and ventilation problems.

The miners object to AMS because they fear it would mean an end to man-operated air checks.

MSHA's new regulations for ventilation plans drew fire from Robert Jennings, a Utah health and safety representative for the UMWA, who said miners would lose their right of appeal of ventilation plans.

"The final rules should provide for miners' determination in ventilation plans," Jennings said. "A coal miner today is not an uneducated idiot. He is a professional who wants the safest possible mine."