Officials told News4 a man was hospitalized after a HAZMAT crew was called to the Shady Grove Metro station Wednesday evening.
Montgomery County Fire crews responded to the scene at approximately 9 p.m.
The man claimed he was exposed to some sort of white powder Wednesday morning at the Metro station, and later returned that evening to report the incident.
All preliminary tests are negative for toxic chemicals, officials said.
The Interstate 370 side of the station was temporarily closed Wednesday night. Rail service was not affected.