Evening classes at Wallace Hall at Wichita State have been canceled Tuesday after a mercury spill in the building.

University officials say a scientific instrument broke, causing mercury to contaminate a laboratory.

After the cleanup is completed, the air quality of the building will be tested at 7 a.m. Wednesday to determine if the building can be safely occupied.

Wallace Hall is home to the electrical and aeronautic engineering department, computer science department and the College of Engineering.

According to the Kansas health department, mercury is “highly toxic.”

“Young children and fetuses are the most vulnerable. Mercury can enter the body through inhalation of mercury vapors or by skin absorption. Mercury will accumulate in body tissues and organs and cause adverse health problems,” a statement from the health department said.

Small amounts of spilled mercury don’t pose as large of a risk, the health department said. Mercury is most dangerous in a vaporized state, which can occur after heating.

The university doesn’t want to take any chances.

“Our first concern is the health and safety of our students, faculty and staff,” said Royce Bowden, dean of the College of Engineering. “We are taking every precaution and doing whatever it takes to ensure that the building is safe before reopening.”