Washington DC chemical leak after CSX freight train derails

A freight train has derailed in Washington DC, spilling hazardous liquid, but no injuries were reported and no evacuation orders were issued.

Fourteen wagons of the CSX freight train overturned near Rhode Island metro station early on Sunday.

Sodium hydroxide, a form of caustic soda, leaked from one wagon, which was later sealed by emergency crews.

Crews also plugged a leak in another wagon after a release of non-hazardous calcium chloride.

The cause of the derailment is unclear.

Sodium hydroxide is a corrosive chemical that can irritate and burn the skin and eyes.

According to the US Centers for Disease Control, while sodium hydroxide is not combustible, contact with moisture or water may generate enough heat to ignite combustible substances.

"We don't know how much leaked," District of Columbia Fire Department Deputy Chief John Donnelly was quoted as saying by Reuters news agency.

"The fumes should not cause you any problems."

CSX said the train had three locomotives and a total of 175 cars - nearly half of them empty, the rest carrying mixed freight.