Cleveland Fire Brigade were called to Caroline Street in Hartlepool at 5.16pm on Thursday, April 21 after the small bottle was discovered.
Fire crews alerted a chemical company who identified the liquid as hydrochloric acid, which is used in industry but also found naturally in the digestive fluids of animals.
The chemical company safely removed the bottle and teams from Cleveland Fire Brigade left the scene at around 8.39pm.
A Cleveland Police spokesperson said: “Police were contacted by Fire Brigade colleagues just before 5.30pm yesterday advising them they were in Caroline Street in Hartlepool and had concerns about a bottle which had been left in the street.
"It was unknown what the contents were however there was not believed to be any specific risk to the public at that time.
"The information was noted and the matter was left in the hand of the Fire Brigade.”