There was an equipment problem at the Phillips 66 (PSX) Rodeo, Calif. refinery, according to a government document made public on Monday.
Sulfur dioxide was burned off after an unspecified problem, according to the filing with the Contra Costa Health Services Hazardous Materials Program. The filing didn't give a date.
Gasses are burned off when purged from refinery units that have been closed.
The refinery outside San Francisco can process 120,000 barrels a day, according to the Phillips 66 website.
Write to Ben Lefebvre at firstname.lastname@example.org