ATCHISON, Kan. (AP) - Authorities say it's safe for residents to return home and for students to go back to school now that a noxious cloud that formed over their northeast Kansas community has dissipated.

The Kansas Department of Emergency Management says the cloud occurred Friday morning when sulfuric acid and hypochlorite were mistakenly combined at the MGP Ingredients plant in Atchison.

The department says 18 people who suffered respiratory problems because of the cloud were taken to hospitals. Their conditions have not been released.

Emergency officials ordered the evacuation of schools and homes near the plant earlier Friday, but lifted the evacuation order when the chemical cloud cleared later in the morning.

MGP produces premium distilled spirits and employs about 300 people at the plant in Atchison, 50 miles northwest of Kansas City.