Children's Healthcare of Atlanta at Egleston's emergency room was closed temporarily Saturday night after a substance brought into the hospital with a patient sickened four hospital workers.

DeKalb County Fire called in its HAZMAT team and evacuated that portion of the hospital for a few hours as a precaution while it worked to identify what later turned out to be pellets used in pool maintenance, Capt. Eric Jackson said Sunday.

The bag of pellets found its way into the hospital with a patient and his mother, who also had been sickened. They and the hospital workers showed signs of nausea, vomiting and dizziness, Jackson said.

Hospital staff put the mother and patient, whose names were not released, in isolation and moved the chemical outside as a precaution before fire officials arrived.

The HAZMAT team identified the chemical, then put the bag of pellets in a biohazard bag for disposal, Jackson said.

Firefighters were first called to the hospital just before 11 p.m., he said.