A union representing Kansas state employees says some officers at the state’s maximum-security prison outside El Dorado are being required to work 16-hour shifts.

The Kansas Organization of State Employees disclosed Friday that it filed a grievance earlier this month with Corrections Secretary Joe Norwood.

KOSE Executive Director Robert Choromanski said the practice is dangerous.

He also said it violates a bargaining agreement between the department and prison employees that keeps officers from being required to work more than 12 hours in a 24-hour period.

Choromanski said eight officers have complained to the union and the practice began in early July. An hours-long disturbance occurred at the El Dorado prison June 29.

Department of Corrections spokesman Todd Fertig declined to comment and called the grievance a personnel matter.