00:53 Industrial Spill Causes Chemical Cloud Highways have been closed and people are being warned to stay inside after a chemical spill at a plant. Meteorologist Ari Sarsalari has the details.

At a Glance At least 18 people are being treated for respiratory problems

Residents north of the plume have been asked to evacuate.

The plume resulted from a grain factory.

Many residents of Atchison, Kansas, are being allowed to return to their homes and go outside, following a scare over a toxic plume of chlorine that hovers over the city on Friday.

City officials told residents via Twitter that it was now safe for them to go outside.

Atchison City Manager Trey Cocking said in a press conference that 18 people were being treated for "respiratory discomfort," and are currently being monitored.

Cocking said the plume was the result of two chemicals that were mixed together inadvertently during the delivery process. There was no explosion at the plant, as several reports indicated.

Officials with the Atchison County Emergency Management Agency told weather.com that the spill occurred at MPG Ingredients, Inc. earlier in the day. They believe the plume is comprised of chlorine.

The city of Atchison said via Twitter that the fog has lifted and the situation is improving.

A lack of wind in the area today could impact the speed of the plume as it moves north over the city, according to weather.com senior meteorologist Jonathan Erdman.

“Unfortunately, there's a pretty stable air mass in place, so that gas plume may hang around for a few hours,” Erdman said. “They could really use a windy day to help disperse it.”

(MORE: Wind forecast for Atchison, Kansas )

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/staticmaps/DCT_SPECIAL10_1280x720.jpg" srcset="https://s.w-x.co/staticmaps/DCT_SPECIAL10_1280x720.jpg 400w, https://s.w-x.co/staticmaps/DCT_SPECIAL10_1280x720.jpg 800w" > Current Winds Near Atchison, Kansas

Local emergency officials originally insisted that people in the direct plume area, north of MPG Ingredients, between 10th Street and 14th Street to shelter in place as the plume moves north. Residents were also warned to close all windows, turn off air and furnaces, and stay indoors.

County officials announced via Facebook that the Atchison County Courthouse closed and employees were evacuated. Several schools in the area were also temporarily evacuated.

A spokesperson from the Atchison Fire Department told weather.com that the leak is currently under control.

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