Ingredients

Look up anything on a label — by its scientific name or the one you know.

2 ingredients · Colorant · Caution

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Colorant Caution
p-Phenylenediamine

The key ingredient in most permanent dark hair dyes and a potent allergen — patch test every time, and never use it on skin ("black henna").

Sensitizer

Also written PPD

Colorant Caution
Toluene-2,5-Diamine

A hair-dye ingredient used in place of PPD in many permanent dyes. It's a strong allergen too — many people allergic to PPD react to it. Patch test before every colouring.

Sensitizer

Also written 2,5-Diaminotoluene, PTD