Do not get me wrong... My sense of smell is more keen too... and I always remove my self from the offending odor/chemical as quickly as practical. I know it is not good for me.
Awareness that these things are not good for us probably has something to do with our negative responses to them.
I just seem to be able to tolerate these things better than I used to... I used to be much more chemically sensitive and extremely intolerant of these things.
Perhaps variations in tolerance has something to do with ones ability to deal with and neutralize the chemical(s) effectively.
Perhaps it has something to do with a focus on dietary minerals - food nutrient density... and use of mineral baths, etc.