SIOUX FALLS, S.D. – The discovery of old, unused research chemicals at a university in northwest Sioux Falls that had turned explosive led to a campus-wide closure Thursday morning.
The University of South Dakota announced the planned evacuation at its Sioux Falls campus near Marion Avenue and 60th Street North after expired peroxide-forming chemicals were identified earlier this week in its Science & Technology Building.
The compounds can become explosive when the formation of crystals occurs, according to the university, which added that the crystals — like those discovered at the Sioux Falls facility — react to friction and shock.
“Following confirmation that peroxide crystals had formed from the chemicals, USD began working with a hazardous materials disposal crew to plan for and execute this disposal,” read a news release issued from USD’s Vermillion headquarters.
A chemical hazmat team informed the university there was no immediate risk if the chemicals remain still, but transporting them to a disposal site brought risk.
Because risk of a reaction would be limited to the disposal route, USD had initially decided to close only the Science & Technology Building during the disposal process, but instead opted to close the entirety of the campus.
“Out of an abundance of caution and for the safety of the responders, the university made the decision to close the USD – Sioux Falls campus,” according to the school, also noting the closure did not disrupt any academic programming.
The campus re-opened Thursday afternoon.