"ScienceDaily (Jan. 20, 2012) Do you get a headache from the perfume of the lady next to you at the table? Do cleaning solutions at work make your nose itch? If you have symptoms prompted by everyday smells, it does not necessarily mean you are allergic but rather that you suffer from chemical intolerance. According to Linus Andersson at Umeå University, this hypersensitivity can be the result of an inability to get used to smells.
Normally your smell perceptions diminish rapidly, as when you enter a friend's apartment. Even though you clearly notice smells just inside the door, you don't think about them for long. For people with chemical intolerance, on the other hand, smells seem always to be present. Psychology researcher Linus Andersson has exposed both intolerant and non-intolerant individuals to smells and compared their reactions."