Skip to content

Your bag

Nothing in here yet.

Three steps is a good place to start.

see the routine
the live free daily

“what's one thing you could do today that's just for you, no one else? what's stopping you?”

today's question →

← the glossary

p-Phenylenediamine

Never allowedReviewed September 18, 2026

PPD · 1,4-Diaminobenzene

The main hair-dye allergen, and a coal-tar derivative. Used to colour a product.

What it does
Colour & shimmer
Part of
Coal tar and synthetic dyes

Every other ingredient, with the same treatment.

open the glossary