(KRON) -- The Chevron refinery in Richmond is experiencing flaring Friday morning due to a “process unit upset,” the company announced at 8:09 a.m. Chevron said its employees were working to minimize and stop the flaring. In a report to the California Governor’s Office of Emergency Services, the company said the flaring event has released more than 500 pounds of sulfur dioxide in the form of vapor as of 7:47 a.m., with the total amount released unknown. “Flares are highly regulated safety devices used in refineries to relieve pressure during the refining process and help keep our equipment operating safely,” the refinery wrote on Facebook. There is no estimated time for the release to be secured. ...read more read less