You could be chemical sensitive. There are chemical free hair care products
. Vanicream Free and Clear has shampoos and conditioners and other hair care products that you could try an dare chemical free. But always remember, before trying any shampoo, always do a test spot first. In cosmotology, I was taught to always do a check test, as you, and even your customer, may not even know they have an allergy to any ingrediant you may be using.