A man has been taken to hospital after being overcome by fumes on a farm outside Omagh.
The incident happened on the Mullagh-arn Road around lunchtime.
It's understood slurry was being mixed at the farm at the time.
The man was treated at the scene before being moved to Altnagelvin hospital.
Incidents involving slurry have claimed the lives of a number of people in Northern Ireland in recent years, including a child.
The Ulster Farmer's Union give official advice on Slurry mixing and say that if possible, it should be done on a windy day.
After starting a pump farmers should leave the mixing area and stay out of the building for as long as possible - at least 30 minutes.
Slurry gas is heavier than air and during mixing will settle in a cloud over the top of the tanks.
Breathing in the area of the gas cloud for even a few moments can cause unconsciousness.
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