A chemical spill at the Lyman Physics Laboratories forced the evacuation of faculty and researchers yesterday afternoon, marking the third spill at a Harvard laboratory this month.

The phosphorous acid spill also resulted in the evacuation of Jefferson and Cruft Laboratories.

The spill occurred at 1 p.m. in the basement machine shop of Lyman, according to Joe Wrinn, director of the Harvard News Office. Wrinn said the machine shop operator first noticed a smell of phosphorous acid and then noticed a leaking container of the chemical.

The operator quickly moved the container under a ventilation hood to control the fumes. The employee then evacuated the building. The Cambridge Fire Department and the Hazardous Waste response team responded to the spill,according to Gerald Rearden, the deputy chief ofthe Cambridge Fire Department.

The machine shop operator was taken toCambridge City Hospital as a precaution andreleased. He exhibited no symptoms of an adversereaction to the chemical, Rearden said.

By 2:30 p.m. yesterday, the spill had beencontained, he said. The leaking drum was placedinto another container and secured.

Harvard professors and researchers use thechemical to clean metal in the shop. Facultymembers use the machine shop to design materialsfor their research. The chemical was described assimilar to battery acid.

Lyman, located behind the Science Center, is aphysical research building. It contains noclassrooms, but does contain researchlaboratories, faculty, staff and visitingscholars' offices and some departmentaladministration offices.

The spill did not appear to pose a seriousthreat to the Harvard community. "Right now, itappears as though it's a very minorcontamination," Rearden said. He noted the fastactions of the worker to contain the spillprevented a more serious contamination.

Yesterday's spill was the third at a Harvardlaboratory this month and the fourth lab-relatedaccident at Harvard in the last few months.

Just last Monday, a chemical spill occurred theSeely G. Mudd Building at 250 Longwood Ave. inBoston, a Harvard Medical School building