Tests on suspicious white powder found in an envelope Wednesday at the Ramsey County Courthouse revealed the substance was harmless, the Pioneer Press reports.
Ramsey County Sheriff's Department spokesman Randy Gustafson says bomb disposal and hazardous material responders were called to the courthouse after 2 p.m. on a report of "suspicious stuff" being found at the violations bureau office.
The Star Tribune reports that an initial test found the powder to be an organic protein.
A second test, however, showed the powder was related to a family of substances that included innocuous material, toxins and ricin, St. Paul Fire Chief Tim Butler told the paper.
Even so, Butler said, authorities were "93 percent" sure that the substance was related to yeast or something similar. He said less than 1/8th of a teaspoon of the powder was found in the envelope.
A third test by the Minnesota Department of Health revealed that the substance carried no safety risks. A fourth test of the powder is underway.
About 35 violations bureau employees had to remain in the building while tests were conducted, but they were eventually released, Minnesota Public Radio reports.
The office was shut down for the rest of the day Wednesday. It is expected to reopen Thursday once the health department concludes its testing of the material.