Madison Fire Department spokeswoman Lori Wirth told Madison.com it hasn't been determined if any arsine gas had been released Wednesday at a North Side building, and investigators were trying to figure it out on Thursday.
Eight employees were in the building when the alarm went off, and they all evacuated safely.
"Team members entered the Alfalight building in full turnout gear to prevent exposure," Wirth said in a news release.
"Crews found the storage cylinders where chemicals are stored, shutting off all the valves and preventing any potential leak," Wirth said.
The gas release was in a building near Madison Area Technical College on the North Side, but no injuries have been reported, according to the Madison Fire Department.
MATC was not evacuated.
Alfalight is at 1832 Wright St., about a block from the MATC campus, and was called in to the Madison Fire Department at 8:07 a.m. Wednesday. Alfalight makes lasers, according to its website.
"We evacuated the building and locked down the building behind it," Wirth said.
A hazardous materials team was at the scene.