Davenport Ridge Elementary School in Stamford was closed to students Wednesday morning after a dry carpet cleaner in a cardboard box in a janitorial closet got wet, reacted with the moisture and emitted an odor, according to officials.
A janitor was taken to Stamford Hospital as a precaution and is expected to be released, according to school officials and the state Department of Energy and Environmental Protection.
Students either stayed on buses or waited at the nearby Greek Orthodox Church as emergency crews checked out the building.
The school system did bring in an industrial hygienist to ventilate the building and ensure the safety of the students and staff, according to DEEP.
Authorities gave the all clear around 9 a.m.