The Air Force says tests have failed to pinpoint what sickened three people at a mail facility at a southern Illinois base.
Environmental tests of the mail center after a suspicious package was found Wednesday turned up "nothing of significance."
Scott Air Force Base spokeswoman Karen Petitt told The Associated Press that it's possible whatever sickened two workers for the U.S. Postal Service and an Air Force serviceman had dissipated by the time tests were conducted.
Earlier in the day, base commander Col. Michael Hornitschek said it was possible the package could have been a have been a "very benign shipment" and that "something had spilled or broke."
The three people were hospitalized Wednesday and a hazmat team responded to the post office at Scott Air Force Base after a suspicious package was discovered.
The three apparently broke out in a rash and were treated at a nearby hospital. Over a dozen others at the mail center were being decontaminated as a precaution at the mail center.
Authorities are directing any base personnel who visited its post office Wednesday and exhibit any abnormal symptoms to report to a Pronto's Pizza, Fox2now.com reported. Loud speakers on the base could be heard warning personnel to avoid the west side of the base, KPLR11.com reported.
The package prompted precautionary evacuations of the base's education center, bowling alley and other services near the mail center.
Garland didn't have any information on what made the package suspicious, although local media reported it emitted a sulphur-like smell.
Garland says the hospitalized people showed no symptoms other than the rash. There is no immediate threat to the community, the base said in a statement.
With the 10th anniversary of the Sept. 11, 2001, terrorist attacks less than two weeks away, Scott spokesman Thomas Kistler said no extra precautions were in place on the base. He said officials are not treating this as a potential terrorist incident.
"I think they're treating it as a normal suspicious package right now," he said.
Col. Michael Hornitschek, the commander of the base, said he believes the package found Wednesday that sent three workers at Scott Air Force Base to the hospital was an isolated incident and has no connection to the approaching anniversary of 9/11.
"We have evacuated an area around the package but we haven't enlarged the evacuation area," he said. "We don't anticipate there's any danger to the rest of the base or to the community as a whole."
Ferrero said the area had been cordoned off although she did not believe there was any immediate danger. She noted that the base routinely performs exercises for incidents like this and was ready to respond.
"We are reacting on the side of caution," she said.
Master Sgt. Jerome Baysmore said "several" firefighters at the base were overcome by heat and treated by on-base medics. The St. Louis Post-Dispatch reported that four firefighters affected.
Traffic flowed in and out of the base through one of the main gates by late morning.
The air base is near Mascoutah, Ill., about 25 miles east of St. Louis, and serves as a global mobility and transportation hub for the Defense Department. The base is home to the U.S. Transportation Command, Air Mobility Command, the 618th Air and Space Operations Center and Air Force Network Integration Center. It is also one of four bases in the Air Force to house both a Reserve unit -- the 932nd Airlift Wing -- and an Air National Guard unit -- the 126th Air Refueling Wing.
The base's Web site says its population is 45,749.
The Associated Press contributed to this report.