Emergency and hazmat crews were called to an industrial lab in Shelton for a reported chemical leak Friday.
The incident happened at Milestone Inc. at 25 Controls Drive in Shelton around 12:30 p.m. Milestone does laboratory testing on consumer products.
A statement from police says an investigation revealed there was a small hydrofluoric acid spill and that vapor from the chemical reached the ventilation system.
Hazmat tests will determine if any chemicals were actually released. No one was injured or exposed, but the building was evacuated as a precaution.