There was an ammonia leak at the StarKist Samoa plant in American Samoa this morning.
Production at the cannery came to a halt for about 40 minutes while the whole plant and office staff were evacuated across the road.
Police, fire, hospital and Environmental Protection Agency vehicles rushed to the cannery after receiving a 911 call.
The StarKist Samoa general manager Brett Butler says an unusually high ammonia reading from an area within the plant was traced to be a leak.
Standard operating procedures required the whole cannery to be evacuated.
Mr Butler says no one required treatment from exposure to ammonia and employees returned to their work stations after 40 minutes without incident.