A cordon was put in place at a hospital after a man was reportedly stabbed and had a substance thrown in his face.
The victim, in his 20s, was taken from the scene in Walton, Liverpool, to Aintree Hospital after emergency services were called at about 6.30pm on Sunday.
The cordon was set up at the hospital as a precaution as tests were conducted on the substance.
Medics later confirmed it did not present any wider risk to others and has been initially assessed as a household substance.
Police thanked members of the public for their patience and understanding as the cordon was removed.
A cordon remains in place at the scene of the assault in Inglis Road as detectives carry out house-to-house, forensic and CCTV inquiries.
Chief Inspector Mark Everard, of Merseyside Police said: “These are the early stages of our investigation into what appears to be a targeted attack.
“If you were in or near to Inglis Road at around 6.30pm and saw or heard anything, come forward right away and we will take positive action.
“This is clearly a serious assault and our focus is now on establishing the exact circumstances to bring those responsible to justice.”
Anyone with information can contact @MerPolCC, 101 or Crimestoppers anonymously on 0800 555 111 with reference number 702.