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.