The company has used its powerful influence with government officials over the past 60 years to keep a federal safety standard in place that failed to protect workers, and Brush supported the standard to sell its product and keep lawsuits at bay, Al Stewart said in closing arguments.

"If they admit that the 2-microgram standard doesn't work, they know folks like you will find them liable," Stewart said to a Jefferson County jury. The federal safety standard limits the amount of dust or fumes workers can be exposed to, setting that limit at 2 microcrams of dust per cubic meter of air.

Four workers from the former nuclear weapons plant and their wives are suing Brush, an Ohio-based company. The four contracted chronic beryllium disease, an often debilitating lung ailment that's caused by inhaling the metal's dust or fumes.

The workers allege that Brush conspired with the federal government to keep information secret, allowing a constant flow of the metal to the defense industry.

"Are we talking about whether men will live or die? Yes," Stewart said of what was at stake in the alleged coverup.

Jurors listened to 13 days of testimony and must decide whether Brush has any liability for the workers' illness and whether the workers filed their suit in enough time under the statute of limitations. The jurors can assign some or all of the blame to Brush, to other companies or to the workers themselves.

If the jury finds Brush liable, the case will continue with a second phase to determine monetary damages.

The case also is being watched across the country because Brush faces more than 70 similar lawsuits, and it's the first time claims about the conspiracy will go to a jury, observers have said. Another 47 workers also are part of the same Jefferson County suit, but how their claims will be handled depends on the outcome of the current suit.

Brush's attorney countered in her closing arguments that the conspiracy idea was ridiculous. She noted that the United Steelworkers of America, one of the main unions at Rocky Flats, and companies such as Dow Chemical and Rockwell International that operated the weapons plant near Arvada, knew the standard didn't protect all workers from the lung disease.

"If this was a conspiracy, it was one of the worst conspiracies," said Sydney McDole. "It's almost ludicrous that we were suppressing information."

But the workers have a bigger problem with their case, McDole said.

The workers can't prove that Brush had anything to do with their getting sick at Rocky Flats, she said.

The company drew a picture of a sloppily run plant with makeshift ventilation or none at all around machines handling beryllium. Evidence showed exposures in the beryllium machine shop and other areas commonly exceeded the safety standard by as much as 1,580 percent.

The workers also testified that they weren't trained about the metal's hazards.

The workers' case is pinned on hundreds of pages of internal company documents and declassified federal records.

One of the most critical is the diary of Brush's president, which admitted in 1951 that the company's workers were getting sick from exposures below the federal safety standard.

Stewart called the document "very important," while McDole said there was no way to know what the diary meant, since the writer has died.