Five fire agencies responded Thursday afternoon to a vegetation fire on Syar Industries property off Highway 221 in south Napa.
The blaze, which was reported shortly after 2 p.m., had burned 19 acres by 3:30 p.m., but firefighters achieved 60 percent containment by then, said Molly Rattigan, the county's public information officer. The acreage estimate has fluctuated as firefighters have improved their mapping of the fire, she said.
The grass and brush fire is confined to Syar property. Firefighters are working to prevent it from spreading to Napa State Hospital property to the north, Rattigan said.
Napa County Fire, City of Napa Fire, American Canyon Fire and Napa State Hospital Fire all fought the blaze, she said.
There were 11 engines, four water tenders, two dozers, four hand crews, two helicopters and two air attack planes fighting the fire, Rattigan said.
The blaze initially sent up a column of gray smoke that was visible from central Napa.