Where It Comes From
Manufactured for use in hair dyes, textile/leather dyes, photographic developers, and rubber chemicals; the dihydrochloride form is more water‑soluble for formulations. [1][2]
How You Are Exposed
Skin contact during hair coloring or black “henna” products; salon and factory work; inhaling dust/aerosols; accidental ingestion or eye splashes. [1][2]
Why It Matters
Can cause lifelong allergic contact dermatitis, eye irritation, and asthma‑like symptoms; high doses may cause methemoglobinemia and hemolysis. Not classifiable as to carcinogenicity (IARC Group 3). [1][2][3]
Who Is at Risk
Hairdressers/barbers; frequent hair‑dye users; workers in dye/printing/rubber production; people with eczema or asthma; individuals with G6PD deficiency; children using black henna. [1][2]
How to Lower Your Exposure
Choose PPD‑free products; avoid black henna; follow label directions and patch‑test; wear nitrile gloves and ventilate; keep off skin/eyes and rinse well; at work use PPE and local exhaust and wash promptly after contact. [1][2]
References
- [1]CDC/NIOSH Pocket Guide to Chemical Hazards: p‑Phenylenediamine (106‑50‑3).
- [2]WHO IPCS Poisons Information Monograph (PIM 415): p‑Phenylenediamine.
- [3]IARC Monographs. p‑Phenylenediamine, Group 3 (not classifiable as to carcinogenicity).