Air samples tested yesterday revealed no asbestos inside the ventilation system of the Investment Building in Towson.
Baltimore County officials ordered the office tower, where 700 state and county employees work, closed Thursday night after an inspection revealed that workers had removed floor tiles containing asbestos a few feet from air-handling equipment in a penthouse utility room.
Owners A.M.G. Realty Partners of New York had earlier launched a $3 million overhaul of the heating and air-conditioning systems at the building, where office workers had complained for years of headaches and other health problems.
But work crews were not supposed to be in the penthouse area, which had not been properly sealed to contain fibers and dust, said George G. Perdikakis, director of the county Department of Environmental Protection and Resource Management.
Richard J. McIntire, a spokesman for the Maryland Department of the Environment, said yesterday that the floor tiles contained 2 percent asbestos. "We ordered the owner to hire a certified firm to do remediation work," McIntire said.
Crews from P.C.S. of Baltimore are expected to work through the weekend to remove the tile debris. A decision has not been made on whether the building will be open Monday.
Lee Baylin, an attorney representing A.M.G. Realty, said he did not know why construction crews had started working in an area where they were not supposed to go. "Everybody is working on solving the problem and getting the building open," Baylin said. "We'll point fingers later."
Building owners face possible fines for allowing asbestos work without a permit, Perdikakis said.
Dozens of people who work at the Investment Building say managers have overlooked their health complaints for years. Recent investigations have determined that the building does not meet the standard for sick-building syndrome.