By Mike Dunn

PHILADELPHIA (CBS) — One floor of Philadelphia City Hall was briefly evacuated this afternoon after a powder was discovered in an envelope mailed to a judge.

The police department’s hazardous materials (“hazmat”) unit and the bomb squad were called to the 4th floor of City Hall about 1:30pm.  The floor was closed to the public for about one hour.

Officials said testing determined that the powder was not dangerous, and the floor was reopened.  Further analysis identified the substance as talcum powder.

The remainder of City Hall was unaffected by the fourth-floor activity.