Officials still have not determined what was in the white powder that led to the evacuation of administrative offices at the Decatur Correctional Center Thursday, but they have determined it was not hazardous.
The powder was in a small, sealed plastic bag that was mailed to the correctional facility.
Inmates were locked down and the administrative offices were cleared.
Corrections officials say operations have returned to normal.
They are not commenting on whether that envelope was addressed to an inmate at the prison, and say the incident remains under investigation.