1,2-Phenylenediamine dihydrochloride

Manufactured for dye and pigment production; used in some hair-dye formulations and as an enzyme substrate/reagent in laboratories [2][3].

Mainly through skin contact when handling powders/solutions; breathing dust or aerosols at work; accidental hand‑to‑mouth ingestion; contact with contaminated surfaces or hair-dye products that contain o‑phenylenediamine [1][2].

Causes irritation and is a skin sensitizer that can trigger allergic dermatitis after repeated or even low‑level contact; IARC classifies o‑phenylenediamine as not classifiable for carcinogenicity in humans (Group 3) [1][2].

Lab staff using colorimetric substrates, dye/pigment and chemical manufacturing workers, hairdressers/barbers using dye products, and people with existing skin allergies or eczema [1][2].

Avoid skin contact; wear chemical‑resistant gloves (e.g., nitrile), eye protection, and lab coats; work in well‑ventilated areas or hoods; minimize dust; use closed kits or pre‑made solutions; clean surfaces and wash hands after handling [1].