Two people are in a stable condition after a major incident at a fish factory in Kilkeel.
Fourteen patients were taken to Daisy Hill Hospital in Newry.
A multi-agency response sprung into operation.
It came after reports of a suspected ammonia leak.
NI Air Ambulance was also involved.
A number of people were treated at the scene and others transferred to Daisy Hill Hospital.
The Southern Trust said the major incident was now being ‘stood down’.
A spokesperson said: “We received a total of 14 patients to the Emergency Department for assessment.
“Two patients are being admitted to the hospital – both are in a stable condition.
“We would like to thank all of our staff and partners in the NIAS and NIFRS for dealing with this incident as calmly and professionally as always and for making sure that all of our patients received the best possible care.”
The Health and Safety Executive will be attending the scene of the suspected leak.