Question Summary:
Why is it impermissible for women to wear perfume in front of ghayr-mahrams and not for men?

Question Detail:

Why is impermissable for a women to wear perfume in front of ghair mehrams but not for men?

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
Allah in His Infinite Wisdom has made different things impermissible for men and women keeping in view the biological differences between the two genders.
 
For example, men are forbidden from wearing gold and silk, while both of these are permissible for women. Likewise, he (salallahu alayhi wa sallam) has stated that women should not wear perfume when they go outside while this injunction is not given to men. [i]  
 
The wisdom and practicality of this command becomes clear when we understand that Allah has defined different roles for men and women. Women have been created alluring and attractive by nature. However, this does not mean that they can be treated as objects and compared to other women on the street. Therefore, to conceal their beauty, women are required to observe the hijab when leaving their homes.
 
Perfume or scent is also a part of beautification but it cannot be hidden like other articles of beauty can. It spreads and attracts attention towards the person wearing it. A believing woman then would be negating her hijab by wearing perfume.
 
Men, on the other hand, do not wear hijab and neither is beauty associated with them the way it is with women. As a result, this injunction does not apply to them.
 
And Allah Ta’āla Knows Best
Sohail ibn Arif,
Student Darul Iftaa
Chicago, USA
Checked and Approved by,
Mufti Ebrahim Desai.
 
  كل عينٍ زانِيةٍ ، والمرأةُ إذا استعطرتْ فمرتْ بالمجلسِ ، فهي كذا وكذا . يعني : زانيةٌ [i]
 سنن الترمذي  الرقم: ٢٧٨٦