A whiff of propane was reported in a University of Minnesota building Wednesday morning, prompting its brief evacuation, a school spokeswoman said.

The report involved Smith Hall, where a science lab mishap injured one person last week, said the U’s Julie Christensen.

Someone in the building detected the “smell of propane” about 8:30 a.m., pulled a fire alarm and called 911, Christensen said.

The building was ventilated and monitored while roughly 100 people were sent out of the building, she added.

Minneapolis fire personnel “found no issues” and an all-clear was declared about an hour later, according to the spokeswoman.

Emergency personnel have yet to determine the source of the suspicious odor, she said.

On June 17, a U chemistry graduate student was injured in a science lab explosion and needed surgery to remove glass from his arm and leg. Walter Partlo, 36, suffered burns and cuts when a chemical compound mixture exploded. The hall was evacuated and reopened that night.