Traces of asbestos are escaping from the Pentagon's crumbling ceilings, federal safety experts said yesterday, stirring a dispute over whether the substance poses a danger to the building's 22,000 workers. A union spokesman said it did, but officials of the General Services Administration disagreed.

Last month, GSA specialists began finding asbestos fibers being released from ceilings, pipe insulation and air ducts throughout the 3.8-million-square-foot building, said Dale Bruce, a spokesman for the agency's National Capitol Region, which operates the Pentagon.

"We don't feel anybody there is in any danger whatsoever," he said.

Officials of the American Federation of Government Employees disagreed. "It is a clear danger," said Fred Small, president of the AFGE's council representing civilian Air Force employes. "We believe any concentration of asbestos can be dangerous."

Small cited studies by the National Institute of Occupational Safety and Health that he said established that hazard. In particular, he said that rats and roaches that infest a building can kick up asbestos and propel fibers into the air.

Workers are removing asbestos-laden ceilings in only a few areas on the Pentagon's fourth and fifth floors, where the asbestos has been found to be "friable," or flaking and being disbursed into the air, Bruce said. Asbestos, commonly used in buildings until the early 1970s as insulation or as a fire retardant, has been linked to cancer and respiratory diseases.

In the future, asbestos will be removed only when scheduled renovation of an area of the 42-year-old Pentagon would disturb the ceiling and disburse the asbestos fibers, Bruce said.

Renovations will be delayed until after tests show that no asbestos is likely to be released during the remodeling, he said.

Bruce added that the highest levels of asbestos found at the Pentagon were .1 fibers per cubic centimeter, well below the standards set by the federal Occupational Safety and Health Administration. OSHA has said that 2 fibers per cubic centimeter is a dangerous level, he said.

Tests at the Pentagon during the past five years failed to detect any asbestos, Bruce said. He added that GSA officials "don't really have an explanation" why tests last month started finding asbestos traces throughout the building. He said one reason might be "improved technology" of air testing devices.

Small said one reason for higher asbestos readings is work performed a few years ago by a GSA contractor who removed asbestos insulation from many pipes and then stored the material above the building's 15-foot ceilings instead of removing it. He said union officials were alerted to the problem last month when workmen installing new lights on the fifth floor cut a hole in the ceiling and loose asbestos fell to the floor.