BREA (CBSLA) — Homes around an aerospace manufacturing firm in Brea were briefly evacuated Thursday morning after a fire led to a hazmat situation.

A fire was reported at Bristol Industries, 630 E. Lambert Road, at about 3 a.m., prompting the evacuation of homes near the structure fire due to hazardous materials concerns. Residents were allowed to return to their homes at about 7 a.m.

The fire also prompted authorities to shut down Lambert Road in both directions between State College Boulevard and Cliffwood Avenue.

The building’s automatic sprinklers reportedly caused acid runoff. Workers were checked for exposure to the chemicals as firefighters put out the flames.