Crews from the state Department of Energy and Environmental Protection have responded to Boehringer Ingelheim, a pharmaceutical company on the Danbury-Ridgefield line, after chemicals were released in a lab there.
The part of the facility where the lab is located is closed, according to state environment officials.
They said pressure built up in a bottle in an unoccupied lab and a small amount of chemicals were released. No one was hurt.
Another bottle with a smaller amount of the same material remained stable, according to DEEP.
The Danbury fire department, State Police and DEEP are at the facility, where they are evaluating the situation, and making plans to enter the lab, remove the second bottle, and prepare it for proper disposal.
An environmental contractor will clean the lab to remove materials that were sprayed.
