Two people were rushed to the hospital Thursday after an ammonia leak at a Valley winery. Ten others were treated at the scene.
Fresno County emergency crews were called to the winery just after 5:00 a.m.
Evacuations were ordered for a one mile radius around the plant on Central Avenue, near Chateau Fresno in Western Fresno County.
Ammonia is used as a cooling agent at most wineries and experts say even a small amount can be dangerous to your health.
Hazmat crews were taken up in the Fresno County Sheriff's Department helicopter to get an aerial view of the winery, making sure the ammonia leak was under control.
The leak was a powerful chemical called anhydrous ammonia which is used commonly at wineries.
Fresno State wine expert, Ken Fugelsang said, "It's the refrigerant, the cooling agent of choice for larger wineries."
Fresno County Coroner, Dr. David Hadden said, "Ammonia is a very toxic substance. It's even been used as poison gas."
The cause of the ammonia leak is still under investigation.