HC Blue No. 2

HC Blue No. 2 1
molecular structure · PubChem CID 36383
AKA: 33229-34-4, HC Blue 2, NCI-C54897, Ethanol, N4-Tris(2-hydroxyethyl)-2-nitro-p-phenylenediamine, COVARINE BLUE W 6122
Synthetic
Not Clean
2,2'-[[4-[(2-Hydroxyethyl)amino]-3-nitrophenyl]imino]bisethanol
Solubility less than 1 mg/mL at 75 °F (NTP, 1992)
Formula
C12H19N3O5
Mol. Weight
285.30
CAS #
33229-34-4
Form
Powder
State
Hc blue 2 is a dark blue to dark brown microcrystalline powder. (NTP, 1992)
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
Allergen Warning
⚠️ PPD (Hair Dye)
Functions
Hair Dyeing
Colors Hair
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed1 review →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
4
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
Not a Skin Irritant
2 studies / 2 not irritating (CIR 80)
Not a Sensitizer
2 studies / 2 not sensitizing (CIR 80)
Not Phototoxic
Animal test found no phototoxicity in the CIR safety assessment (CIR 80)
Mixed Eye Irritation Results
2 studies / 1 irritating / 1 not irritating / reactions minimal to moderate (CIR 80)
Concentration Guide
0%50%100%
Reg. limit 2.8%
EU regulatory limit: 2.8%. Can cause allergic reaction Source: EU Cosmetics Regulation (EC) 1223/2009, Annex III (Restricted Substances), Entry 247.
Regulatory Status
USA✔ permitted
EU✔ permitted
JAPAN✔ permitted
CANADA✔ permitted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR