Antioxidants
REACH
4-Hydroxy-TEMPO
CAS Number
2226-96-2
EC Number
218-760-9
Abbreviation
TEMPOL
What is 4-Hydroxy-TEMPO?
4-Hydroxy-TEMPO (CAS 2226-96-2), commercially known as TEMPOL, is a stable nitroxide radical.
Where is 4-Hydroxy-TEMPO used?
- Polymer and resin manufacturing: polymerization inhibitor and radical scavenger in monomer streams
- Process stabilizer against premature crosslinking or degradation during production and storage
- Pharmaceutical synthesis: controlled radical mediator and antioxidant stabilizer
- Personal care: oxidative stability in formulations
- Catalyst in selective oxidation reactions, including conversion of primary alcohols to aldehydes
- It serves as a catalyst in fine chemical and API synthesis workflows.
Commercial specifications
- Purity specifications commonly ranging from 97% to 99%+
- Technical and high-purity grades
- Packaging from small laboratory quantities to bulk industrial supply
Other Names (Synonyms)
Tempol
What are the physical properties of 4-Hydroxy-TEMPO?
Melting Point 71-73 °C
Boiling Point 302.58°C (rough estimate)
Density 1.0402 (rough estimate)
Flash Point 146°(295°F)
Appearance solid
Color Orange
Form Crystals or Crystalline Powder
Water Solubility soluble
Vapor Pressure 0.025Pa at 20℃
Refractive Index 1.4350 (estimate)
pH 8.2 (20g/l, H2O, 20℃)
Log P 0.56 at 25℃
How is 4-Hydroxy-TEMPO classified and handled safely? Learn More
Danger
GHS05· Corrosive GHS07· Irritant GHS08· Health Hazard
Hazard Statements
H302 H302
H315 H315
H318 H318
H319 H319
Precautionary Statements
P260 P260
P261 P261
P264 P264
P270 P270
Which trade and regulatory codes apply to 4-Hydroxy-TEMPO?
HS Code 29333999
Storage Class 11 - Combustible Solids
WGK (Germany) 1