(KAIR)--The two companies found guilty of causing the formation of a toxic chlorine gas cloud over Atchison in 2016 have been fined $1 million each.

According to a news release from the office of U.S. Attorney Stephen McAllister, Atchison-based MGP Ingredients and Kansas City’s Harcros Chemicals have paid the fines.

They were sentenced during a hearing in federal court in Topeka Wednesday.

Both companies previously pleaded guilty to negligently violating the Clean Air Act, a Class A misdemeanor.

In their pleas, they admitted that on October. 21, 2016, a greenish-yellow chlorine gas cloud formed at MGP Ingredients’ Atchison facility when 4,000 gallons of sulfuric acid were mistakenly combined with 5,800 gallons of sodium hypochlorite. The Atchison County Department of Emergency Management ordered community members to shelter in place and to evacuate in some areas. Approximately 140 individuals including members of the public, first responders, and employees of the two companies, sought medical attention.