LIMESTONE – The mysterious powder found in an envelope mailed last week to the Defense Finance and Accounting Service at the Loring Commerce Centre still had not been identified as of Monday afternoon.

Even though the nature of the substance is not known, tests done by the state health laboratory have confirmed those done in the field last Thursday morning, which found that the powder was not a biological substance, Vernon Ouellette, head of the Aroostook County Emergency Management Agency, said Monday.

The orange powder was discovered at about 4 p.m. Wednesday in an envelope containing vouchers and invoices sent to DFAS from Dyess Air Force Base in Texas.

A packaging tape dispenser with the powder on it also was discovered in the envelope.

The National Guard 11th Civil Support Team, which is trained to handle incidents of potential mass destruction, including those that are biological in nature, was activated, as was the Madawaska Volunteer Fire Department Hazardous Materials Response Team and more than 20 other agencies.

Close to 80 DFAS employees were quarantined for 11 hours before the National Guard determined that the powder did not pose a chemical or biological threat.