Police were called by the London Ambulance Service at 18:38hrs on Thursday, 2 November to Yarmouth Crescent, Tottenham N17, after a man was sprayed with a noxious substance.
The victim, believed to be in his 30s, was treated at the scene and then taken to hospital for treatment. His condition is not believed to be life-threatening or life-changing.
It is believed that there were two suspects on a moped, and this was an attempted robbery.
No arrests; enquiries continue.
If you have any information about this incident, call Haringey Police on 101 or Crimestoppers on 0800 555 111.