What is the ruling on using perfumes if we do not know the percentage of alcohol in them?

Scholars have differed regarding the intoxicating nature of alcohol found in perfumes and the impurity of Khamr (wine/intoxicants). They have leaned towards the view that Khamr is impure and that the alcohol found in perfumes is intoxicating and impure. Therefore, if perfumes contain alcohol, they are impure, whether the proportion is small or large, unless the alcohol undergoes a complete transformation and becomes another substance.