2,4-DIAMINOPHENOL

📋 Quick facts

Description: 2,4-DIAMINOPHENOL — HAIR DYEING.

All Functions: HAIR DYEING

Quick Facts:

• Category: other
• Regulatory Note: Prohibited in the EU

Proven Benefits At A Glance:

• 2,4-diaminophenol is a chemical used in dyes and photographic developers
• Research shows it can cause kidney damage at high doses in animal studies
• It showed some evidence of cancer-related effects in male mice but not rats
• The toxicology studies used doses given by mouth (gavage), not applied to skin
• No skincare benefits for this ingredient are documented in the available research

⚗️ Chemical Overview

On the basis of the data included in this report, the CIR Expert Panel concludes that 2,4-Diaminophenol and 2,4-Diaminophenol Dihydrochloride are safe for use in hair dyes at concentrations up to 0.2% (as the free base). 2009 RE-REVIEW – The Expert Panel noted that 2,4-Diaminophenol Dihydrochloride is now termed 2,4-Diaminophenol Hydrochloride. RN given refers to parent cpd

Source(s): Medical Subject Headings (MeSH), Cosmetic Ingredient Review (CIR), via PubChem

📊 Comedogenicity

🛡️ Safety rating

Safety tier is a starting heuristic from regulatory status and comedogenic rating, not a dermatological verdict — see our Terms for the full disclaimer. Research confidence reflects how many real cited studies back this ingredient, not the strength of their findings.

🌍 Regulatory Status

💧 Skin Type Compatibility

⚠️ Don’t Combine With

📚 Research & Evidence

🔬 The Science

2,4-diaminophenol is an industrial chemical with established uses in dye manufacturing and photographic development (Natl Toxicol Program Tech Rep Ser, 1992). The available research on this ingredient focuses entirely on toxicology and safety testing, not on skincare applications. The National Toxicology Program conducted extensive animal studies administering 2,4-diaminophenol dihydrochloride (the salt form) by mouth over 16 days, 13 weeks, and 2 years. Key findings include: #1: Kidney damage was the primary organ system affected—renal tubule necrosis appeared in both rats and mice at elevated doses, and the severity of kidney lesions increased with dose and study duration (Natl Toxicol Program Tech Rep Ser, 1992).

#2: In the 2-year studies, male mice showed increased incidence of renal tubule adenomas (a type of tumor), which the researchers determined to be related to chemical exposure; however, rats showed no renal tumors at any dose tested (Natl Toxicol Program Tech Rep Ser, 1992). #3: Genetic toxicology testing showed the chemical was mutagenic in one bacterial strain (Salmonella TA98) only when metabolic activation was present, and positive in a mouse lymphoma cell assay, though results varied across different test systems (Natl Toxicol Program Tech Rep Ser, 1992). One analytical chemistry study describes using 2,4-diaminophenol as a component in laboratory fluorescent probes for detecting chromium and measuring pH, but this research is not relevant to skincare (Anal Methods, 2023).

No studies in the provided sources examine 2,4-diaminophenol as a skincare ingredient, its effects on skin, or any cosmetic benefits. The toxicology studies used internal administration (gavage feeding) in animals, not topical application to skin.

📄 Related Research

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

• Wu Y et al. (2023). One step synthesis of highly photoluminescent red light-emitting carbon dots from O-phenylenediamine and 2,4-diaminophenol as fluorescent probes for the detection of pH and Cr(VI). Anal Methods.
• National Toxicology Program (1992). NTP Technical Report on the Toxicology and Carcinogenesis Studies of 2,4-Diaminophenol Dihydrochloride (CAS NO. 137-09-7) in F344/N Rats and B6C3F1 Mice (Gavage Studies). Natl Toxicol Program Tech Rep Ser.

🧴 Products Containing 2,4-DIAMINOPHENOL