A $15 million class action suit filed today against Burlington Industries charged the nation's largest textile manufacturer with deliberately withholding medical information from workers it knew were suffering from byssinosis, or "brown lung disease," so they would continue working under unhealthy conditions.

The suit, filed in U.S. District Court in Greenville, S.C., on behalf of mill workers who contend they contracted the chronic lung disease by breathing in cotton dust at the company's F.W. Poe plant there, also alleges that Burlington defrauded employes of workmen's compensation benefits when they became too sick to work.

Filed jointly by the Southern Poverty Law Center in Montgomery, Ala., and the Carolina Brown Lung Association, the suit also names as defendants Dr. Harold R. Imbus, Burlington's corporate medical director, other company physicians, and the Liberty Mutual Insurance Co. of Boston. Liberty Mutual provides Burlington and other textile companies with coverage against workmen's compensation claims.

The suit charges that Burlington knew, as a result of dust-level measurements taken by Liberty Mutual as part of its regular safety inspections prior to 1970, that employes at the Poe mill and other company plants would eventually be disabled because of the "dangerous and excessive levels of cotton dust" they worked in.

It also says medical surveillance by the company showed that 20 workers at the Greenville plant were suffering from byssinosis and 61 from chronic bronchitis in 1971. The suit alleges that workers contracted other chronic lung diseases, including emphysema, from breathing cotton dust.

Burlington did not tell any of the mill workers involved that they had lung disease, or that their problems were caused by cotton dust inhalation, according to the pleading filed in the suit.

"None of these people were told cotton dust was dangerous, nor were any workers told the results of the breathing tests Burlington gave them," said Paul Cline, a retired textile worker who is president of the Greenville chapter of the Brown Lung Association. "Burlington knew some workers' breathing scores were getting worse and they allowed those people to keep working," he said.

Cline said that "brown lung victims were left sick and disabled with no income other than Social Security" when the Poe plant was shut down in 1977. The suit contends that plaintiff David Burdette failed the breathing test every textile mill where he applied for a job after the plant closed.

Carol Hillman, public relations director for Burlington Industries, said it would be "highly inappropriate" for the company to respond to the charges since it knew of the suit only through news reports.

"As a corporation," said Hillman, "we are considered a leader in the field of medical surveillance." She said Burlington has installed $40 million worth of equipment to cut down the dust levels in its 20 cotton mills.