A 45-year-old man is due in court today charged with criminal damage, after chemicals were poured on a clothing rack outside a Richmond shop.
The police were called to the store in Queen Street yesterday afternoon as the man ran away and was pursued by members of the public.
The area was closed for about two hours while the fire service decontaminated the scene.
Detective Sergeant Lex Bruning praised the quick-thinking actions of the public which led to the arrest.
He said the offending was unusual and the police were keen to establish what the motive was.
A woman who was taken to hospital as a precautionary measure was unharmed in the incident.