1:20 p.m. update: The York County HAZMAT Team has determined the white substance found at the York County Prison this morning was non-hazardous, county spokesman Carl Lindquist said.

The three employees who went to a local hospital did not suffer any ill affects and are OK, he said.

Prison mailroom operations are expected to resume as normal today.

Original story: Three York County Prison employees sought evaluation at a local hospital after potential exposure to an unknown white substance, York County officials said.

The three employees were opening mail in the prison mailroom at about 11:30 a.m. Friday when the white powdery substance was discovered, York County spokesman Carl Lindquist said.

The employees suffered no immediate ill effects, but drove themselves to a local hospital for evaluation as a precaution, he said.

Until the substance can be identified, the mailroom is closed and the HVAC airflow to the area has been temporarily turned off. There is no impact on other prison operations, including visitation.

No inmates were exposed to the powder. The mailroom is located in a non-secure area of the facility separate from inmate housing.

Police have been notified, and the York County Hazmat Team is on site and investigating.