Phenyl Methyl Pyrazolone

AKA: MCI-186, MCI 186, Edaravone, 89-25-8, 3-METHYL-1-PHENYL-2-PYRAZOLIN-5-ONE, Radicut, Norphenazone, 1-Phenyl-3-methyl-5-pyrazolone, Developer Z
Synthetic
Not Clean
OriginPhenyl methyl pyrazolone is synthesized from organic precursors within the heterocyclic aromatic compound family. It is produced through cyclization and oxidation reactions of substituted pyrazole intermediates.
3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-2-phenyl-
Solubility less than 1 mg/mL at 73 °F (NTP, 1992)
Formula
C10H10N2O
Mol. Weight
174.20
CAS #
89-25-8
Form
Powder
State
1-phenyl-3-methyl-5-pyrazolone appears as white to off-white powder or crystals. (NTP, 1992)
Skin Types
●all-skin-types
Best For
General
Functions
Hair Dyeing
Antioxidant Protection
Locks In Moisture
Fights Bacteria
Colors Hair
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
4
CIR
Safe as used
Pregnancy
—
CIR Safety Findings
Not a Sensitizer
1 study / 1 not sensitizing (CIR 103)
Mixed Eye Irritation Results
2 studies / 1 irritating / 1 mixed / reactions mild (CIR 103)
Skin Irritant in Testing
1 study / 1 irritating / reactions slight (CIR 103)
Regulatory Status
USA✔ permitted
EU✔ permitted
JAPAN✔ permitted
CANADA✔ permitted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR