DH has allergies/sensitivities to chemical fragrances developed over years working as a chemist. I really refused to believe it until I tried some perfume at the mall one time, and within 3 minutes of me walking into the same room with him when I got home, he was a dripping, sneezing mess and his throat started swelling up. Natural oils don't do it, and various perfumes cause different levels of reaction in him (he's ok around Marc Jacob's "Lola" in small amounts, for example, but Chanel #5 drops him).
Anyway, having once pooh-pooh'ed the notion, I now at least understand that some folks really do have bad reactions to those things. By the way, if anyone needs a very slightly used bottle of Chanel #5 I know where you can get one at a deep discount.