WASHINGTON — The Mine Safety and Health Administration published a proposed rule Monday calling for underground coal mines to have a place for workers to be safe if they cannot escape quickly in the event of an accident.

The rule marks another step in the agency's "unprecedented" pace in getting out rules for the Mine Improvement and New Emergency Response Act, known as the MINER Act, which Congress passed two years ago this week, according to MSHA head Richard Stickler.

"While miners must continue to follow their first instinct — which is to withdraw from the mine in the event of an emergency — this proposed regulation calls for a protected, secure space that creates a life-sustaining environment when escape is not possible," Stickler said.

In the last 18 months, MSHA has published six final rules in the Federal Register, issued an Emergency Temporary Standard and proposed four additional rules, including the latest one on underground refuges that appeared in the Federal Register on Monday, according to MSHA.

While critics on Capitol Hill have complained it has taken too long for MSHA to implement provisions of the MINER Act, Stickler said rules have never come out at this rate before.

Stickler also said MSHA has hired more than 300 inspectors over the past two years to scour the nation's underground coal operations for unsafe working conditions. The agency has 750 inspectors with the 322 new hires. But because of resignations and retirements, the new hires represent a net increase of 163 inspectors.

The agency has been beefing up its work force in an effort to increase inspections after a series of mining disasters from West Virginia to Utah. Forty-seven miners were killed on the job in 2006, one of the deadliest for miners in more than a decade. Six miners and three rescue workers also died in 2007 at the Crandall Canyon mine in Utah, while 15 mining fatalities have been reported nationwide since Jan. 1.

A 40-year-old coal miner was reported dead Monday after a below-ground accident at the Harmony Mine near Mount Carmel, Penn., about 90 miles northwest of Philadelphia. Federal and state inspectors were dispatched to the mine, owned by UAE Coal Corp. Associates.

A report last year by the inspector general found that MSHA had failed to carry out inspections at 107 of the 731 underground coal mines operating in 2006, or 15 percent of the total.

Stickler said he also has embarked on a plan to ensure inspectors complete required visits to every coal mine in the nation, aided by $10 million earmarked for overtime pay this year.

"We're doing everything we can to see that we make all the mandated inspections," he said.