Medics and firefighters responded to the scene, in the 800 block of South Weller Street, just after noon after receiving a report that a worker's arm had become stuck in heavy machinery at the plant.
Crews were able to extricate the man and rush him to Harborview Medical Center.
It was not immediately known how the accident took place. The worker's name was not released.
This is a developing news story. More information will be posted as it becomes available.