(KAIR)--A Kansas City, Kansas-based chemical company has pleaded to charges in connection with a toxic chlorine cloud that formed over Atchison in 2016.

According to a news release from the office of U.S. Attorney Stephen McAllister, Harcros Chemicals, Inc. on Friday entered a guilty plea to negligently violating the Federal Clean Air Act.

According to the plea agreement, the company is expected to pay a $1 million fine, the same amount that co-defendant, Atchison-based MGP Ingredients, is expected to pay. MGP pleaded guilty in November.

In the plea from Harcros, the company admitted that a greenish-yellow chlorine gas cloud formed on October 21, 2016 when 4,000 gallons of sulfuric acid were mistakenly combined with 5,800 gallons of sodium hypochlorite. The toxic cloud led Atchison County Emergency Management officials to order Atchison residents to shelter in place, while evacuation was ordered for some areas.

Approximately 140 people, including members of the public, first responders, and employees of MGP and Harcros, sought medical attention.

Sentencing for Harcros is scheduled for May 27.

According to the release, the company could be sentenced to probation for up to five years.