Ruling on Selling cosmetics

The ruling on working in such places depends on the details. 

1 – If you are selling these things to people who you know will use them for the purposes of haram wanton display (tabarruj), then it is not permissible. 

2 – If you are selling them to people who you know will use them for permissible kinds of adornment, then it is permissible. 

3 – If you do not know anything about the person who is buying them, then the basic principle is that it is permissible.

It is not permissible to sell them if the vendor knows that the one who buys them is going to use them in ways that Allah has forbidden, because that is a kind of helping in sin and transgression. But if he knows that the purchaser is going to use them to adorn herself for her husband or he does not know anything, then it is permissible for him to deal in them.

 See Fatawa al-Lajnah al-Daa’imah, 13/67. 

And Allah knows best.