Most permanent hair dyes include the hair color precursor para-phenylenediamine (PPD). It
is also, regrettably, a well-recognized powerful contact allergen that, when exposed to the …

Most of the permanent hair dye products contain p-phenylenediamine (PPD), a well-known
skin sensitizer. PPD may cause cutaneous reactions and leads to allergic contact dermatitis …

Paraphenylenediamine (PPD) is one of the main ingredients used in permanent hair dyes. It
is, however, known to cause allergic contact dermatitis and potentially serious systemic …

Many dyes for long-lasting hair coloring contain aromatic amines that undergo oxidative
polymerizations, resulting in allergic contact dermatitis, with the potential to develop serious …

The strong sensitizing potencies of the most important primary intermediates of oxidative
hair dyes, p-phenylenediamine (PPD) and p-toluylenediamine (PTD, ie 2-methyl-PPD) are …

Abstract para-Phenylendiamine (PPD) and its ring-methylated analogue, para-
toluenediamine (PTD), are primary intermediates (precursors) for azo dye synthesis …

Most commercial permanent hair dyeing technologies are based on the oxidative process of
p-phenylenediamine and its derivative materials. However, concerns about their …

RATIONALE Although para‐phenylenediamine (PPD) is known to cause severe allergic
contact dermatitis in consequence of autoxidation and/or skin metabolism pathways, it is …

Para-phenylenediamine (PPD) is a chemical that is widely used in hair dyes. Multiple safety
and regulatory agencies have categorized PPD as a potent sensitizer. In addition, PPD has …

Abstract Background Para-Phenylenediamine (PPD) is a commonly used dye intermediate
in permanent hair dye formulations, and exposure to PPD has been associated with allergic …