The plant is part of the Pepsi Bottling Group, and local press reported that a leak was detected by electronic sensors on site, which prompted the evacuation.
Todd Davis, a reporter for NBCDFW.com, wrote that firefighters were able to isolate a small leak and that 90% of the site was reopened within two hours.
He added that no injuries were reported, while officials said that no businesses or neighborhoods were affected by the leak.
Ammonia is toxic and may be harmful to humans if inhaled in concentrations. According to the US Environmental Protection Agency, effects can range from irritation to severe respiratory injuries and even death, while skin exposure results in a chemical-type burn.