Wurzburg said the 20-year-old woman was in the nightclub's restroom Monday night and took the spray canister from her friend's purse, TheLocal.de reported Wednesday.
The woman did not check the canister's label before spraying it on herself, believing it to be deodorant.
The pepper spray quickly spread through the building and the club was evacuated, police said. Two women were treated for eye injuries.
Police said they are looking into whether the woman will face negligent bodily harm charges.