4-NITRO-O-PHENYLENEDIAMINE

EU conditions: To be printing on the label:
Hair colorants can cause severe allergic reactions.

📊 Comedogenicity

📚 Research & Evidence

🔬 The Science

4-NITRO-O-PHENYLENEDIAMINE (also called 4NOPD) is a synthetic aromatic amine—a type of organic chemical with a benzene ring structure. According to a 1981 Teratology study, researchers tested this compound on pregnant mice to understand potential developmental risks. #1: At doses of 256 mg/kg/day and higher, 4NOPD caused a significant increase in birth defects (malformed fetuses) in mouse studies. #2: At these same high dose levels, the chemical also reduced weight gain in pregnant dams during pregnancy and caused a significant reduction in average fetal weight. The study was designed to evaluate whether the chemical could cause maternal toxicity (harm to the mother) alongside any fetal effects.

It’s important to note that these studies involved direct injection of very high doses into pregnant animals—a scenario quite different from typical skincare exposure. The research does not address safety at the trace or dilute levels that might theoretically appear in cosmetic formulations, nor does it provide any data on human use or safety. The 1981 publication date also means more recent safety research may exist elsewhere. This ingredient is not commonly marketed as an active skincare ingredient in contemporary products.

💧 Skin Type Compatibility

⚠️ Don’t Combine With

🧴 Products Containing 4-NITRO-O-PHENYLENEDIAMINE

📄 Related Research

Matched by search — not necessarily verified support for every statement above.

• Marks TA et al. (1981). Teratogenic evaluation of 2-nitro-p-phenylenediamine, 4-nitro-o-phenylenediamine, and 2,5-toluenediamine sulfate in the mouse. Teratology.