4. Propelyne Glycol

This chemical acts as a penetration enhancer and keeps products from melting in high heat or freezing when it is cold. It is used as a humectants in hair products and a preservative. Found in shampoos and conditioners typically, this ingredient is typically found in shampoos and conditioners but could provoke allergic reactions and cause irritation.

What hair ingredients are you concerned could be potentially damaging your hair health?