There are a number of different reasons for this the most common of which is the hair dye itself.
However, symptoms may last for days to weeks after the last time a person dyed their hair.
These characteristics make PPD a potent contact antigen able to induce allergic reactions.
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For this reason, some European countries, including Germany, France, and Sweden, have banned PPD.
Most hair dyes that are labeled as being hypoallergenic will not contain PPD as an ingredient.
This chemical serves to provide the pigment in certain light and medium brown hair dyes.
Centers for Disease Control and Prevention.The National Institute for Occupational Safety and Health.
