Hi, can someone please explain to me about PPD. I know it's a toxic chemical and my dermatologist told me to avoid it. I read on your site that you have a lower amount in your color compared to others but I don't understand how you know you have a lower amount compared to others - how do you know their formulas? Is it true that you have just a trace amount in your color? What exactly do you mean by a trace amount? Thanks for explaining this.