Honolulu firefighters and police reponded to a report of a suspicious envelope in the Prince Kuhio federal building at 300 Ala Moana Blvd.

The suspicious item was a business envelope, about 4-by-10 inches in size, found in the Social Security office and reported shortly after 4:30 p.m. Tuesday.

Employees alerted authorities as part of their standard procedure because the addressee and the envelope’s appearance matched suspicious packages reported in the past, said Honolulu fire Capt. Terry Seelig. He said the envelope wasn’t delivered by mail.

Firefighters checked for radiological, chemical, or biological threats, but didn’t find any. Firefighters also called police to help check for explosive hazards.

"We’re still considering it to be a possible threat, but not at all terrorism related," Seelig said.

He said the letter did not appear to be related recent events, such as the death of Osama bin Laden, which prompted some military bases in Hawaii to heighten their security levels.