Capitol Police briefly closed D Street Northeast on Tuesday afternoon following reports of an unidentified substance in the Hart Senate Office Building parking garage.

An officer on routine patrol noticed what appeared to be either dust or smoke coming from a dumpster near the garage’s loading dock at 2:15 p.m., department spokeswoman Jessica Gissubel said.

“He wanted to further investigate to make sure it was not a fire,” she said.

After approaching the dumpster, the officer noticed a burning sensation in his lungs. He was treated at the scene and released, Gissubel said.

Tests conducted by the Capitol Police hazardous materials squad and the D.C. Fire Department indicate the substance was not toxic, Gissubel said, adding that the tests did identify the substance.

During the incident, the department closed D Street between First and Second streets but did not evacuate the building.