An undergraduate class held in the University Museum lecture hall was evacuated yesterday afternoon when police responded to a call reporting a "suspicious odor" coming from a nearby chemistry laboratory.

The fumes were released during a chemistry experiment in the Mallinckrodt Laboratories on Oxford Street. One person was given oxygen treatment, but no serious injuries were reported, said Harvard University Police Department (HUPD) spokesperson Peggy McNamara.

The laboratories, however, were not evacuated, said Alan K. Long '79, laboratory director of the Chemistry and Chemical Biology Department.

"It was not a gas leak. There was no danger," Long said.

About 150 students in "Foreign Cultures 34: Mesoamerican Civilizations," taught by Bowditch Professor of Central American and Mexican Archaeology and Ethnology Professor William L. Fash, were evacuated from University Museum 1 at about 11:50 a.m., students said.

"Basically it was just like, 20 minutes before the end of class. We could smell the gas. Then 10 minutes before class ended, the TF hurried up to the stage and gave the professor a piece of paper," said Adam N. Cederbaum '97.

"It was pretty funny. [Professor Fash] was like, 'Oh, there's a gas leak. Let's get out of here.' Everyone was happy to get out of there 10 minutes early," Cederbaum said.

Police reports said the fumes resulted from "exhaust released on the roof of Mallinckrodt...[which] can occur when building humidity is very high."

High humidity intensifies odors. The exhaust system of the building carries those odors to people outside the building, Long said.

"It smelled like a gas stove," said a female lab employee. "I left for lunch. When I came back it was gone."

The employee stressed that all people who work in the labs are prepared to deal with such situations.

"This is not the first time [this has happened]," she said. "When you work in a chemistry laboratory, you kind of expect this kind of thing."