When coal miners undergo annual retraining for using emergency oxygen packs, the session usually takes place in a well-lit classroom.

"There is no stress put on you whatsoever," said Joe Spiker, interim associate director of mining extension services at West Virginia University and expert in SCSR training.

Miners must get into the proper position, crouched low with their cap light on the ground illuminating the self-contained self-rescuer. They have to demonstrate how to put the device on -- including goggles and nose clip -- and how to open the device, activate it and describe how to insert the mouthpiece.

But they never actually breathe through it.

With self-contained self-rescuers costing $650 apiece, it's simply too expensive to expend one for each miner every year during the retraining.

As a result, miners typically do not experience what it's like to breathe on an SCSR -- until they find themselves in an underground emergency, surrounded by smoke and gas, their life on the line.

"They can be difficult in the conditions that people are expected to put them on, having to put them on so rapidly. And it's an uncomfortable piece of equipment to maneuver, particularly if the mine is filling with smoke," said Jack Spadaro, former head of the National Mine Health and Safety Academy in Beckley, W.Va.

"You should be able to use it at least once for it to be effective training."

But that would be an exception to general practice, according to Mr. Spiker. "There's not a great training model out there that can be used time and time again."

One thing first-time users notice is the resistance the device puts up to normal breathing, he said.

"When you're sitting at your desk, there's no resistance. But with certain types of SCSRs, when they start getting near expiration, they become very hard to breathe through. You have to sort of suck the air out of that unit. There's still plenty of air but it becomes harder to breathe."

Had federal safety standards proposed in 1999 been adopted, though, coal miners' training in the use of emergency oxygen packs would be markedly different.

A draft copy of a standard proposed by the U.S. Mine Safety and Health Administration in 1999, obtained by the Pittsburgh Post-Gazette, calls for "expectations training" -- teaching miners not only how to don an SCSR, but what it will feel like to breathe once it's on.

"When a miner does not know what to expect, the miner may believe that the SCSR device is not functioning, or the oxygen supply has been depleted," the proposed rule states. "This may result in the miner removing the mouthpiece in a hazardous atmosphere which could result in death."

The description, 6 years old, sounds haunting in light of 12 miner deaths at Sago in January and five more in Harlan County, Ky., last weekend.

In both instances, surviving miners said SCSRs were not working properly. Others wonder if infrequent training played a role.

"The training, unfortunately, focuses primarily on the donning aspect of it and not the process," said J. Davitt McAteer, who was head of the U.S. Mine Safety and Health Administration in 1999 and proposed the more frequent training sessions.

That proposed rule was withdrawn in September 2001, following an administration change at the agency.

The 1999 proposal also called for storing caches of oxygen inside the mine, another part of MSHA's emergency temporary standard implemented this year after 12 miners died at Sago, and limiting the service life of SCSRs to five years.

Mr. Spiker said some mine operators are trying to make the retraining more realistic, requiring miners don the SCSR in the dark.

His office also has a 28-foot cargo van with a simulated non-toxic smoke environment. Miners not only have to put the SCSR on, they must then navigate a maze while in the dense smoke.

The intent is that the training will make an emergency less unfamiliar, Mr. Spiker said.

"I'm not sure that donning an SCSR once a year is sufficient. I think you can forget to do certain things in one year's time," he said.