A facility in Anniston, Alabama that trains first responders is suspending its use of chemical and biological substances after it mistakenly used lethal ricin during training exercises.
The Federal Emergency Management Agency says it's halting use of the chemicals through January at the Center for Domestic Preparedness in Anniston.
The agency made the announcement earlier this week on a website set up to provide updates on the center, where thousands of firefighters, paramedics and others have trained.
No students have been reported to have been harmed at the center. But FEMA has asked the Department of Homeland Security's Inspector General to investigate how the deadly toxin came to be used during exercises in which workers don protective gear while learning to handle hazardous substances.
FEMA says workers intended to order a non-lethal form of ricin from a vendor.