Falcon School District 49 said two Falcon High School students and a teacher were taken to the hospital after having allergic reactions to chemicals used during a chemistry lab.
The incident happened on the morning of Thursday, January 30, 2014.
A note that was sent to Falcon High School parents by Principal Cheryl DeGeorge says that one student developed symptoms of an allergic reaction shortly after the lab was completed. A second student developed a similar reaction about an hour later.
The science room and adjacent rooms were immediately evacuated and the fire department was called. El Paso County's Hazardous Materials Unit also was called to the school to investigate.
About 125 students who had been in the affected room were evaluated. A few did show minor symptoms of allergic reaction. Overall, the conditions of those affected did not appear serious.
The district says that students affected by the incident had an allergic reaction to a sulfur compound created when a group of students inadvertently mixed in an additional chemical. It says a reaction to sulfur can cause a rash, shortness of breath and scratchy throat.
D-49 says Thursday's incident will not impact the class schedule on Friday.