WINSTON-SALEM, N.C. (WGHP) — Workers at Collins Aerospace in Winston-Salem were evacuated on Monday due to a HAZMAT situation, according to the Winston-Salem Fire Department.

Around 200 employees were forced out of their offices after hazardous gas filled one of the rooms. The call reporting the gas buildup came in around 10:30 a.m.

Firefighters say the business in the 2500 block of Empire Drive was evacuated due to high levels of sulfur dioxide and hydrogen gas from overcharged backup batteries. The chemicals are poisonous and can be flammable.

Crews removed the batteries and ventilated the building.

No injuries were reported.

A responding fire captain tells FOX8’s Rasheeda Kabba that HAZMAT officials found four times what’s considered dangerous levels of sulfur dioxide and hydrogen gas in the building.

“Based on the levels we were detecting, they would’ve probably become overcome with the chemicals and possibly been hospitalized,” said Captain John Powell with the WSFD. “So it’s a very dangerous chemical to be around if you don’t know you’ve got that kind of gas going on.”

Employees are expected to return to work in the building on Tuesday.