Many emails concerning soap, will write this email concerning soap. Wash with a mild shampoo is better than soap. Any soap that is in a bar uses etidronic acid. Pure soap, Simple soap, are names given because they have taken out perfume, but it still uses etidronic acid and other ingridiants, if you go on the website of the type of soap you want to know about, it will say the ingridiants it uses. Copy and paste this wiki article about etidronic acid into your full web browser. en.wikipedia.org/wiki/Etidronic_acid Vanessa the Google girl.