4-Hydroxypropylamino-3-Nitrophenol
AKA “4-((3-Hydroxypropyl)amino)-3-nitrophenol, Colorex RBN, Rot BN, Plakatrot Z, Covariane Rouge W 3127, HC Red BN, Phenol”
Synthetic
vote to see if the hive agrees
Ingredient Facts
4-Hydroxypropylamino-3-Nitrophenol
AKA: 4-((3-Hydroxypropyl)amino)-3-nitrophenol, Colorex RBN, Rot BN, Plakatrot Z, Covariane Rouge W 3127, HC Red BN
Synthetic · Hair Dyeing · EWG: 5
Plant-Derived
Synthetic
Clean
A synthetic colorant that delivers rich, long-lasting hair color. Works as a key component in hair dye formulations to create vibrant, even color results.
Formula
C9H12N2O4
Mol. Weight
212.20
CAS #
92952-81-3
Plant-Derived
Synthetic. Synthesized from nitrophenol precursors and aliphatic amine compounds through organic chemistry reactions. Produced via nitration and subsequent reduction or amination of phenolic intermediates.
Function
Hair Dyeing
Benefits
Colors Hair
Traditional Use
A synthetic hair dye ingredient developed in the mid-20th century. Engineered as a permanent hair color precursor to produce stable, long-lasting color.
Skin Types
all-skin-types
Best For
Target
General
Melanin-Rich Skin
Suitable
Pregnancy Safe
No
EWG Score5
CIR Safety Findings
ewg-5, medical-approval, all-shades-safe
Concentration Guide
2.6%
0%4%
Reg. Limit
EU regulatory limit: 2.6%. (a) To be printed on the label: The mixing ratio. “ Hair colourants can cause severe allergic reactions. Read and follow instructions. This product is not intended for use on persons under the age of... Source: EU Cosmetics Regulation (EC) 1223/2009, Annex III (Restricted Substances), Entry 205
Regulatory Agencies
Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR