Massey Energy chief Don Blankenship, embattled by safety questions after a West Virginia coal mine explosion killed 29 miners in April, went on the offensive this week. He sent four governors, including Kentucky Gov. Steve Beshear, a letter claiming that federal coal mine regulators mandated an unsafe ventilation plan at mines such as Upper Big Branch in Montcoal, W.Va.

The company also claims that the Mine Safety and Health Administration doesn't allow coal dust scrubbers to be used on its continuous miner machines, allowing for a dangerous accumulation of dust.

Massey asked state agencies to review MSHA's policies.

"Ironically, perhaps the single biggest challenge to achieving safe mining is the current behavior of MSHA," the letter concludes.

MSHA and Kentucky's Energy and Environment Cabinet have received the letter Tuesday and are reviewing it before responding, officials said.

The letter says MSHA saw success with a particular ventilation process in Pennsylvania, where coal seams contain high concentrations of methane. Longwall mines, which employ 1,000-foot-long machines that slice through coal and allow "gob" or waste to settle in the void behind, in Pennsylvania were able to encapsulate the methane in the gob and allow it to be siphoned off in a pipeline and sold.

Longwall mines such as Upper Big Branch in southern West Virginia and other regions work in seams with lower concentrations of methane, so putting the explosive gas in a pipeline isn't done. Such a ventilation plan forces the methane to remain in the mine and build up to explosive levels behind safety seals, Massey said.

Massey would rather use high-volume fans and less-circuitous curtain systems to quickly vent methane gas in those types of mines, the company said.

Read more of this story at Kentucky.com