Jose Melena, 62, was reportedly found shortly before 7 a.m. Thursday in a cooking device at the Bumble Bee Foods plant.
Erika Monterroza, a spokeswoman for the California Division of Occupational Safety and Health, said it was unclear how the worker ended up inside the device known as a "steamer machine." The state agency has launched an investigation.
Bumble Bee Foods spokesman Pat Menke expressed condolences to Melena's family in a written statement. Menke says operations at the canning facility will be suspended until Monday.
The Associated Press contributed to this report.