A statement from Cummings said a "putty-like substance on the outside of the front door" was found by his staff when they arrived for work Wednesday morning at his Baltimore district office.
"The police advised my staff not to enter the building. The bomb technician determined the substance was not explosive, and that there was no active threat," the statement reads in part.
Baltimore Fire Department spokesman Ian Brennan said the substance was removed by the city's hazardous materials team and turned over to the FBI for investigation. He added the FBI has taken charge of the investigation, the Washington newspaper Roll Call reported.
Cummings is the ranking member of the House Oversight and Government Reform Committee.