UV-328
CAS Number
25973-55-1
EC Number
247-384-8
What is UV-328?
UV-328 (CAS 25973-55-1), also marketed as Tinuvin 328, is a benzotriazole-class UV absorber used to protect organic materials from photodegradation caused by UV radiation.
Where is UV-328 used?
- Coatings and industrial paints: extends service life of exterior finishes on metal, wood, and plastic substrates
- Automotive OEM and refinish coatings: maintains gloss retention and prevents yellowing in clear coat systems
- Plastics: incorporated into polyolefins, PVC, and engineering polymers for long-term outdoor durability
- Adhesives, sealants, and elastomers: prevents surface cracking in construction and glazing
- It absorbs UV light in the 300–385 nm range and dissipates the energy as heat.
Commercial specifications
- Purity: 99% minimum by HPLC
- Packaging: 25 kg bags to bulk quantities
Other Names (Synonyms)
2-(2H-Benzotriazol-2-yl)-4,6-ditertpentylphenol|Phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylpropyl)-|Tinuvin 328|VN99CPK4TI|Phenol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentyl-|CHISORB 328|CYASORB UV 2337|2-(2H-Benzotriazol-2-yl)-4,6-bis(1,1-dimethylpropyl)phenol
What are the physical properties of UV-328?
Melting Point 84 °C
Boiling Point >180 °C
Density 0.958 g/cm³
Color Off-White to Pale Yellow
Form Solid
Vapor Pressure 0Pa at 20℃
Log P 7.3 at 25℃
How is UV-328 classified and handled safely? Learn More
Warning
GHS08· Health Hazard GHS09· Environmental Hazard
Hazard Statements
H372 Causes damage to organs through prolonged or repeated exposure
H373 May causes damage to organs through prolonged or repeated exposure
H410 Very toxic to aquatic life with long lasting effects
H413 May cause long lasting harmful effects to aquatic life
Precautionary Statements
P260 Do not breathe dust/fume/gas/mist/vapours/spray.
P264 Wash … thoroughly after handling.
P270 Do not eat, drink or smoke when using this product.
P273 Avoid release to the environment.
Which trade and regulatory codes apply to UV-328?
HS Code 2933.99.8290
Storage Class 11 - Combustible Solids
WGK (Germany) 2