What Is P-phenylenediamine?

P-phenylenediamine or PPD is an ingredient used in hair dye products. It is used as the coloring agent in most hair dyes. It is also sometimes used in temporary tattoos. When used in boxed dyes it is mixed with an oxidizing ingredient. Unfortunately when oxidized PPD can cause allergic reactions for those who experience PPD allergies.

An allergy to hair dye, while uncommon, can be serious. An allergy to hair dye can present as stinging or burning on the scalp, blistering, swelling of the scalp, or in other areas that haven’t touched the dye such as face hands, or feet. Darker hair dyes such as black or brown dye often contain higher concentrations of PPD.


the good: Helps to color the hair.

the not so good: Can cause allergic reactions and irritation in some people.

Who is it for? All skin types except those that have an identified allergy to it.

Synergetic ingredients: Works well with most ingredients.

Keep an eye on: If you are allergic to PPD there are alternatives to this ingredient.

What Are The Benefits P-phenylenediamine?

PPD is the coloring ingredient in some hair dyes. Hair dye works by using an ingredient such as ammonia to open up the layers of the hair so that the dye or color can access the shaft of the hair. Then lightening agents such as bleach lighten the hair allowing the coloring agents such as PPD to become trapped in the hair. 

Is P-phenylenediamine Safe?

According to the Cosmetic Ingredient Review Expert Panel, a group responsible for evaluating the safety of skincare and cosmetic ingredients. In their review, they noted that PPD is safe for use in its current uses and concentrations. 

While there is a risk of an allergic reaction when using PPD it is uncommon and there are alternatives if you do experience a reaction.

Aeby, P, et al. 2009. ‘Skin Sensitization to p-Phenylenediamine: The Diverging Roles of Oxidation and N-Acetylation for Dendritic Cell Activation and the Immune Response’, Journal of Investigative Dermatology, vol. 129, is. 1, pp. 99-109.


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