Is it permissible to use denatured alcohol in perfumes, and is it permissible to use perfumes that contain a small percentage of ethyl alcohol that does not cause intoxication?

Alcohol is the intoxicating substance in Khamr (wine/intoxicant), and it is not permissible to use it if it has mixed with something before its transformation (Istihala). In such a case, it is considered impure (Najis) and its use is not permissible, because "what intoxicates in large quantities, a little of it is forbidden" and "every intoxicant is Khamr, and every Khamr is forbidden."

However, if alcohol undergoes a complete transformation (Istihala) during manufacturing into a non-intoxicating substance before being mixed with anything else, then it becomes pure due to the removal of its intoxicating characteristic.