SAN FRANCISCO (Map, News) - Wispy plumes of smoke, liquids frothing out of beakers and loud explosions are all well-documented outputs of chemistry experiments, but University of San Francisco officials realized yet another effect of student lab work: potent odor.

An entire building on the USF campus was evacuated for 1½ hours on Monday after faculty at the Harney Science Center began noticing a suspicious-smelling banana scent wafting through the halls.

San Francisco Police and Fire Department officials rushed to the scene, only to discover later that the odor was the result of a simple experiment conducted by students in an organic chemistry class.

The students were in the midst of creating isopentyl acetate, a particularly smelly compound that is used to test the effectiveness of gas masks and respirators, according to USF spokesman Gary McDonald.

“The compound is basically a very smelly banana oil,” McDonald said. “It is pretty much harmless stuff, but it stinks.”

McDonald said a lack of communication within the faculty department led to the evacuation.

“The class conducting the experiment apparently hadn’t warned everyone in the building about it,” McDonald said. “It was probably an overabundance of caution, but in our chemistry building, it always best to be on high alert.”

After making a sweep of the building, fire and police officials confirmed there were no safety hazards or injuries and allowed the students to return to class, according to a report released by the SFPD.

wreisman@examiner.com