Emergency crews responded to Burns Elementary School in Hartford Monday after several people were exposed to a white powder.
Hartford Public Schools spokesman John Fergus said a balloon with a white substance was found outside and brought into the building.
Fire officials said students playing outside found the balloon, which burst. Two children and two adults were exposed, fire officials said. Police said 14 students and two teachers who were in the area were quarantined. No one was hospitalized and no one showed any signs of illness, officials said.
Fire officials said testing determined the substance was not hazardous or drugs, but it was not immediately clear what the substance was.
The Department of Energy and Environmental Protection is investigating.
Fergus said as a precaution the school called a Code Yellow, which means students were held inside the building. Anxious parents gathered around outside the school Monday afternoon awaiting an update.
Sulaica Berrios said her 6-year-old daughter was exposed.
"I hope so, that’s what they say but we don’t know for sure what it is. We are going to take her to the emergency room to double check everything is fine," she told NBC Connecticut.
Police do not believe there is any criminal aspect to the incident.