The incident took place in Bridgeport at Bassick High School, around 8:15 a.m., Thursday, Nov. 10.
Preliminary reports indicate the building was being evacuated and numerous students were affected by the substance, said Scott Appleby, director of Emergency Management for Bridgeport.
Bridgeport fire, police, and ambulances have responded, Appleby said.
No word yet from school officials.
This is a developing story. Check back to Daily Voice for updates.
Click here to follow Daily Voice New Canaan and receive free news updates.