Detectives say ammonia was sprayed during an alleged attack in Cardiff.
Four teenage boys and a 20 year-old man suffered minor injuries after the incident on City Road at around 2.45pm on Sunday afternoon (5th September).
All five were discharged from hospital on the same day.
No one has been arrested, but it's believed those involved were known to each other.
A South Wales Police spokeswoman said: ''Despite initial reports from the scene, it has been confirmed that the clear liquid sprayed during the assault was not acid and is now believed to be ammonia.''
''Ammonia is commonly used in dyes and cleaning products.''
Part of City Road was cordoned off for several hours after the attack and the public were told to stay away from the area.
Anyone with mobile phone or dashcam footage of the incident is being urged to come forward.