"I'm not even sure what you mean by "chemical sensitivity".

One example of it is they you are feeling okay then someone walks near you with a lit cigarette and when you get a whif of the smoke suddenly many muscles start aching or you get a bad headache. Things like cigarette smoke,perfume, diesel fumes, fumes from cleaning products, paint fumes, the odor of candle burning, and other chemicals can be triggers. Some foods are triggers as well and cause muscle ache and/or headache. What chemical sensitivity means is that certain things that irritate most people at high concentrations irritate chemically sensitive people at much lower concentrations.