Background: Finding alternative hair dyes for individuals allergic to para-phenylenediamine (PPD) has been difficult. Newer permanent and demipermanent hair dyes that have replaced PPD with para ...

There are a ton of hair dyes that are free of ammonia, alcohol, and p-phenylenediamine (PPD, a chemical that helps open up your hair cuticle to let the dye in). These ingredients aren't bad or ...

The most common allergic reactions to hair dye chemicals are dermatitis of the ... Cross-sensitization means that it not only makes you sensitive to PPD but you become responsive to all of its ...

The vast majority of reactions to hair-dye products are caused by PPD. [4–6] In past years, PPD was used in permanent hair dyes but not in semipermanent dyes. More recently, PPD has been used in ...