OriginHC Yellow No. 4 belongs to the azo dye chemical family, synthesized from aromatic compounds and nitrogen-containing precursors. It is produced through diazotization and coupling reactions of aniline derivatives to create the stable yellow colorant.
2-[bis(2-Hydroxyethyl)amino]-5-nitrophenol
Solubility less than 0.1 mg/mL at 68.9 °F (NTP, 1992)
Formula
C10H14N2O5
Mol. Weight
242.23
CAS #
59820-43-8
Form
Powder
State
Canary yellow fluffy powder. (NTP, 1992)
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
Functions
Hair Dyeing
Colors Hair
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory0 listings
🛡️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 55)
Not a Sensitizer
4 studies / 4 not sensitizing (CIR 55)
Not Phototoxic
Animal test found no phototoxicity in the CIR safety assessment (CIR 55)
Eye Irritant in Testing
1 study / 1 irritating (CIR 55)
Dermal Absorption 0.12–0.15%
2 results from in vitro tests in the CIR safety assessment (CIR 55)
murphy