Around 11:30 a.m. Monday officials were notified of a type of powdery substance in the mailroom at the Curran-Fromhold Correctional Facility on the 8200 block of State Road.
Two workers who came in contact with the substance were quarantined.
20 people were evacuated.
The fire department and hazmat crews were called in.
The incident was cleared by the afternoon and the powder was determined not to be a hazardous substance.