NAPLES, Italy — Patients and staff at the U.S. Naval Hospital Naples were quarantined for five hours Wednesday after a servicemember reported an unknown substance while opening mail.

While disaster preparedness personnel in biological suits tested the residue, employees and patients remained in the hospital until the all-clear was given at 2:10 p.m.

“NSA disaster preparedness has determined there is no risk to patients or staff,” said Lt. Susan Henson, base spokeswoman. “The tests were negative for chemical or biological agents.”

At 8:55 a.m., a galley staff member reported that when he opened his personal mail, a small puff of white powder with a bad odor came out.

The hospital duty crew and safety team responded and notified security. No one was allowed to enter or leave the building, which was shut at 9:15 a.m.

Disaster preparedness personnel didn’t find any powder.

Henson said that though they tested the residue in the envelope and determined there was no threat, they didn’t know what the residue was.

Also responding to the scene were the fire department, hazardous material response team, security, Naval Criminal Investigative Service and the Italian carabinieri and polizia.

NCIS gave the envelope to the carabinieri for further testing. Henson said no one became ill as a result of exposure.

During the quarantine, the base Web site, AFN and All Hands e-mails told personnel that patients in need of urgent care should report to the Capodichino Clinic.

The hospital captain, director of clinics and head of laboratory talked to patients and visitors as they left the building.

Patients who had scheduled appointments can contact the clinic to reschedule.

Sign Up for Daily Headlines

Sign up to receive a daily email of today's top military news stories from Stars and Stripes and top news outlets from around the world.

Sign Up Now