Urey Hall in Revelle College was evacuated on the morning of Friday, Nov. 9 because of a chemical hazard. At 7 a.m., officials learned that a dangerous chemical had crystallized in the basement of Urey Hall.

Campus Safety Officials called the San Diego Fire Department, San Diego Hazmat and the San Diego County Hazardous Materials Division, who together helped them decide on the best method to use to safely get rid of the chemical. The building’s perimeter was blocked off for five hours.

The chemical, an industrial solvent called Decalin, forms explosive organic peroxides when exposed to air. A physics graduate student had spent Thursday night working with the chemical for a light-scattering experiment. The student realized the chemical became unstable when exposed to air when trying to figure out how to dispose of it. The Decalin was in a test tube. The student contacted the campus safety officials at 7 a.m. on Friday morning. After the campus safety officials assessed the situation, they called the city and county hazardous materials crews and the bomb squad at 8:30 a.m.

The HAZMAT crews and bomb squad decided that the best response was to remove the chemical from the building and then destroy it using a blasting cap.

“The chemical was moved to outside the building, which removed any threat that might have been associated with any further transportation of the chemical,” Director of UC San Diego Environmental Health and Safety Garry MacPherson wrote in an email sent to students Nov. 9 at 1:20 p.m.

A blasting cap is a small, sensitive explosive device used to detonate large, less sensitive explosives. The crews used the blasting cap to destroy the material around 12:15 p.m. on a landing outside of the building.

Two emails were sent to students at 12:48 p.m. and 1:20 pm. to explain the safety threat behind the closure of the building. Students were allowed to re-enter the building following the detonation of the chemical.