British Transport Police are appealing for information after a bottle of hydrochloric acid was found on a Northern Rail train at Middlesbrough station shortly after 7 o'clock on Sunday evening.
The station was evacuated for a time and buses replaced train services.
4 fire appliances attended the incident along with 3 special appliances and 3 officers.It is believed the acid was in a soft drink bottle and caused the smell of burning when some of the liquid leaked from the container.
More top news
Emma Jesson brings you Sunday night's forecast
Cold and clear with widespread frost on Sunday night. Sunny Monday then showers
A number of Britons are feared stranded on Mount Everest after the Nepal earthquake triggered a deadly avalanche on Saturday.