Police were called at 7.20am and specialist officers attended the scene to conduct tests.
Brompton Road and Hans Road, which run alongside the famous department store, were closed causing large traffic queues. They have since reopened.
There were no reports of anyone suffering illness.
— Carlos Ghawi (@carlos_ghawi)February 25, 2020
Scotland Yard said: “Officers have dealt with an incident after a chemical was thrown at a building in Kensington and Chelsea.
“Police were called at 07.20am on Tuesday, February 25. A noxious substance had been thrown on the outside of a restaurant at the location.
⛔ EMERGENCY SERVICES INCIDENT ⛔ The A4 Brompton Road (SW3/SW1X) at the junction of Hans Road. The road is closed northbound due to a emergency services incident. Use an alternative route. Traffic is stationary with tailbacks now reaching Cromwell Gardens. Expect delays.— TfL Traffic News (@TfLTrafficNews)February 25, 2020
"There are no reports of anyone suffering ill effects during the incident.
“Local roads were closed while emergency services dealt.
“Specialist officers have attended the scene and conducted tests.
“As a result of their action local roads have been reopened. The matter is being investigated as act of criminal damage.”
A spokesman added that no arrests have been made and enquiries continue.