The U.S. Mine Safety and Health Administration on Friday finalized a rule that requires stronger underground mine seals, but does not toughen seal standards as much as studies by two other government agencies suggested was needed.

MSHA more than doubled the minimum strength requirement for all seals built after Oct. 1 in the nation's more than 620 underground coal mines, in one of the more significant safety reforms initiated after the January 2006 Sago Mine disaster.

Agency officials also required additional methane sampling of sealed areas in an effort to avoid a repeat of Sago, where 12 miners died after a massive explosion in a sealed area of the International Coal Group mine in Upshur County.

"Certainly, the final rule will provide miners a much greater protection than they had before," said Phil Smith, a spokesman for the United Mine Workers union.

However, the final rule, published in Friday's Federal Register, continues MSHA's previous discounting of studies by the National Institute for Occupational Safety and Health and the U.S. Army Corps of Engineers.

"If MSHA allows operators to use seals, then the law requires the seals to be explosion proof," said Nathan Fetty, a mine safety lawyer with the Appalachian Center for the Economy and the Environment. "But if MSHA doesn't plan for the worst-case scenarios, how is it going to assure that each and every seal can withstand an explosion."

Since 1969, federal law has required coal operators who want to seal off mined-out areas to build all underground seals so that they were "explosion proof." In a 1992 rule, though, MSHA essentially defined "explosion proof" to mean able to withstand blast forces of 20 pounds per square inch.

In that 1992 rule, MSHA cited a 1971 Bureau of Mines study that they said made the case for the 20-psi standard. But that study, by the late researcher Donald W. Mitchell, noted that federal standards for mine seals on government property, dating back to 1921, required seals to be more than twice as strong as the 20-psi rule.

Mine seals are widespread, with estimates ranging into the thousands at hundreds of mines across the coalfields. Throughout the 1990s, regulators said and did little about them, despite a series of lightning-induced explosions in sealed areas of mines in Alabama and West Virginia.

Seals drew new, national attention with Sago, on Jan. 2, 2006. Still, regulators did little, until five more miners died in a May 20, 2006, explosion at the Kentucky Darby Mine in Harlan County, Ky. Two days after the Darby disaster, MSHA issued a temporary moratorium on the use of lightweight, alternative seals like those at Sago and Darby. Two months after that, MSHA announced that it was - without actually rewriting its regulations - going to require that all seals withstand at least 50 pounds per square inch of force.

Then, in May 2007, MSHA issued an emergency temporary standard to require stronger seals. The emergency action gave MSHA nine months, until late February 2008, to finalize a new seal rule. In June 2006, Congress passed the MINER Act, which required MSHA to increase the 20-psi standard by mid-December 2007.

So, the rule finalized Friday was several months late, according to either legal deadline. It had been under review by the White House Office of Management and Budget since early February.

MSHA's final rule kept with the outline of its original emergency rule to require stronger seal construction on a three-tiered approach modeled generally after a NIOSH study.

New seals would have to withstand pressures of at least 50 pounds per square inch when the atmosphere inside a sealed area is monitored and maintained without explosive methane concentrations. New seals in areas that are not being monitored or maintained inert must withstand pressure of at least 120 pounds per square inch, according to the final rule.

The U.S. Mine Safety and Health Administration on Friday finalized a rule that requires stronger underground mine seals, but does not toughen seal standards as much as studies by two other government agencies suggested was needed.

MSHA more than doubled the minimum strength requirement for all seals built after Oct. 1 in the nation's more than 620 underground coal mines, in one of the more significant safety reforms initiated after the January 2006 Sago Mine disaster.

Agency officials also required additional methane sampling of sealed areas in an effort to avoid a repeat of Sago, where 12 miners died after a massive explosion in a sealed area of the International Coal Group mine in Upshur County.

"Certainly, the final rule will provide miners a much greater protection than they had before," said Phil Smith, a spokesman for the United Mine Workers union.

However, the final rule, published in Friday's Federal Register, continues MSHA's previous discounting of studies by the National Institute for Occupational Safety and Health and the U.S. Army Corps of Engineers.

"If MSHA allows operators to use seals, then the law requires the seals to be explosion proof," said Nathan Fetty, a mine safety lawyer with the Appalachian Center for the Economy and the Environment. "But if MSHA doesn't plan for the worst-case scenarios, how is it going to assure that each and every seal can withstand an explosion."

Since 1969, federal law has required coal operators who want to seal off mined-out areas to build all underground seals so that they were "explosion proof." In a 1992 rule, though, MSHA essentially defined "explosion proof" to mean able to withstand blast forces of 20 pounds per square inch.

In that 1992 rule, MSHA cited a 1971 Bureau of Mines study that they said made the case for the 20-psi standard. But that study, by the late researcher Donald W. Mitchell, noted that federal standards for mine seals on government property, dating back to 1921, required seals to be more than twice as strong as the 20-psi rule.

Mine seals are widespread, with estimates ranging into the thousands at hundreds of mines across the coalfields. Throughout the 1990s, regulators said and did little about them, despite a series of lightning-induced explosions in sealed areas of mines in Alabama and West Virginia.

Seals drew new, national attention with Sago, on Jan. 2, 2006. Still, regulators did little, until five more miners died in a May 20, 2006, explosion at the Kentucky Darby Mine in Harlan County, Ky. Two days after the Darby disaster, MSHA issued a temporary moratorium on the use of lightweight, alternative seals like those at Sago and Darby. Two months after that, MSHA announced that it was - without actually rewriting its regulations - going to require that all seals withstand at least 50 pounds per square inch of force.

Then, in May 2007, MSHA issued an emergency temporary standard to require stronger seals. The emergency action gave MSHA nine months, until late February 2008, to finalize a new seal rule. In June 2006, Congress passed the MINER Act, which required MSHA to increase the 20-psi standard by mid-December 2007.

So, the rule finalized Friday was several months late, according to either legal deadline. It had been under review by the White House Office of Management and Budget since early February.

MSHA's final rule kept with the outline of its original emergency rule to require stronger seal construction on a three-tiered approach modeled generally after a NIOSH study.

New seals would have to withstand pressures of at least 50 pounds per square inch when the atmosphere inside a sealed area is monitored and maintained without explosive methane concentrations. New seals in areas that are not being monitored or maintained inert must withstand pressure of at least 120 pounds per square inch, according to the final rule.

In other areas, where explosive methane concentrations are likely or conditions such as bottom mining might increase blast forces, seals must be designed to withstand pressures of more than 120 pounds per square inch.

MSHA estimated that the rule will cost mine operators nearly $40 million a year, or about 0.30 percent of all revenues for underground mines nationwide. The rule will save a yearly average of about two miners' lives, MSHA estimated.

"This final rule assures that miners can rely on seals to protect them from the hazardous and sometimes explosive environments within sealed areas," MSHA said in a 29-page Federal Register notice announcing the rule.

MSHA again discounted a NIOSH recommendation that seals on some large mined-out areas that are not going to be monitored should be able to withstand pressures of more than 640 pounds per square inch. MSHA also again dismissed the findings of a Corps of Engineers study - which MSHA initially tried to keep secret - that found the Sago blast could have involved forces of up to 1,300 pounds per square inch.

MSHA said data needed for the type of study conducted by the corps was not available, and that much of the information corps experts used was "speculative."

"It looks like MSHA's washing its hands of the issue, rather than doing everything it can to protect miners," said Fetty, who submitted written comments urging MSHA to tighten its rule based on the corps study.

Luke Popovich, a spokesman for the National Mining Association, said the final rule is tougher in some respects than what MSHA originally proposed. For example, methane sampling of some sealed areas would have to occur every 24 hours, rather than on a weekly basis, as originally proposed.

However, the final rule also gives local MSHA officials more flexibility to approve site-specific seal plans.

"This is important, as it will permit MSHA field personnel - those with the best understanding of each mine's unique conditions - to implement the rule to best serve the miners at that given operation," Popovich said.

Ronald Wooten, director of the West Virginia Office of Miners Health, Safety and Training, said state regulators now have 30 days to review the final MSHA rule and report to Gov. Joe Manchin about what, if any, changes the state should make in its own seal rules.

"It's a good, tough rule," Wooten said. "There are a number of safeguards, and it will change the way sealing is conducted in the future."

Wooten said the rule might prompt some mine operators to avoid sealing mined-out areas and instead revert to the older practice of ventilating those areas and conducted routine inspections of them.

To download a copy of the final rule, go to http://edocket.access.gpo.gov/2008/pdf/08-1152.pdf

To contact staff writer Ken Ward Jr., use e-mail or call 348-1702.