Six were treated for dizziness and two were being checked as a precaution at Harborview Medical Center, a fire department spokeswoman said.

The call came in at 8:11 a.m. at the ship "Hyundai Emperor," which was docked at Terminal 5 on the West Seattle side of the Duwamish waterway.

Firefighters investigated for nearly three hours to find the source of the odor, which the victims described as like "fertilizer."

Video from Chopper 7 showed firefighters in moon suits being decontaminated after they checked the ship for the odor.

"We have a container that has an organic phosphorous pesticide in it. We did air monitoring right around that container, didn't have any positive hits for any vapors in the area," said Deputy Chief Jim Fosse, of the Seattle Fire Department.

Fosse said firefighters found a small puddle below the container, but couldn't determine what it was.

Firefighters turned the case over to the terminal operator, and to Foss Environmental, which will try to determine the problem before workers get back on the ship.