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Specialty Additives Available — Bulk Only

UV-328 (Benzotriazole UV Absorber)

BTA
CAS 25973-55-1 · Formula C22H29N3O · MW 351.5 g/mol

This product is restricted and not supplied; compliant UV absorber alternatives are available for coatings, plastics, and adhesives.

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HS Code
2933.99
At a Glance
Material Family
Specialty Additives
Record Type
Pure compound
Primary Role
Corrosion Inhibition · UV Protection
Solubility
In water, log -1.37
Functional Roles
Corrosion Inhibition UV Protection
Industries Served
Coatings & Construction Industrial Manufacturing Oil & Gas Textiles Water Treatment
Applications & Use Cases
  • ▸ Plastics stabilization: UV absorber for polyolefins, PVC, and polyacrylates.
  • ▸ Coatings: Light stabilizer for clear and automotive coatings.
  • ▸ Adhesives and sealants: UV protection in adhesive systems.
  • ▸ Outdoor articles: Stabilizes outdoor furniture and films.
Physical Properties
Physical Description
Dry powder, pellets or crystals, or solid
Appearance
White to yellow powder or crystals
Solubility
In water, log -1.37
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2933 . 99
Chapter 29
Organic chemicals
Heading 29.33
Internationally harmonized (WCO HS)
Subheading 2933.99
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
25973-55-1
Molecular Formula
C22H29N3O
Molecular Weight
351.5 g/mol
IUPAC Name
2-(benzotriazol-2-yl)-4,6-bis(2-methylbutan-2-yl)phenol
PubChem CID
33263
InChI Key
ZMWRRFHBXARRRT-UHFFFAOYSA-N
Synonyms & Trade Names
2-(2H-Benzotriazol-2-yl)-4,6-ditertpentylphenol Phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylpropyl)- 2-(2H-Benzotriazol-2-yl)-4,6-di-tert-pentylphenol UV-328 Tinuvin 328 Phenol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentyl- CHISORB 328 CYASORB UV 2337 UV328 UV 328 2-(2H-Benzo[d][1,2,3]triazol-2-yl)-4,6-di-tert-pentylphenol 2-(3,5-Di-tert-amyl-2-hydroxyphenyl)benzotriazole C22H29N3O 2-(benzotriazol-2-yl)-4,6-bis(2-methylbutan-2-yl)phenol 2-(2'-Hydroxy-3',5'-di-tert-amylphenyl)benzotriazole 2-(2-hydroxy-3,5-di-tert-pentylphenyl)benzotriazole 2-(2-Hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole 2-(2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylpropyl)phenol 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole
Full Description

Restricted substance — RawSource does not supply UV-328

UV-328 (CAS 25973-55-1) is listed under Annex A (elimination) of the UN Stockholm Convention on Persistent Organic Pollutants (adopted at COP-11, May 2023) and is prohibited under the EU POPs Regulation (EU) 2019/1021 (in force from 4 August 2025, with limited time-bound exemptions). It is also a REACH Substance of Very High Concern (PBT/vPvB; Candidate List 2014). RawSource does not manufacture, supply, or quote UV-328.

For UV protection in coatings, plastics, and adhesives we supply compliant benzotriazole, benzophenone, and triazine UV absorbers: UV-P (comparable to Tinuvin P), UV-234 (comparable to Tinuvin 234), UV-360 / bisoctrizole (comparable to Tinuvin 360), UV-531 / octabenzone (comparable to Cyasorb UV-531), UV-1130 (comparable to Tinuvin 1130), UV-1577 (comparable to Tinuvin 1577). Browse all UV absorbers & light stabilizers in our chemical index.

UV-328 (CAS 25973-55-1) is a benzotriazole-class ultraviolet light absorber. It is incorporated into plastics, coatings, and adhesives to absorb UV radiation, with established use in polyolefins, polyurethanes, PVC, polyacrylates, and epoxies.

Solutions Using This Product

Process-solution guides on this site that specify this chemistry:

Frequently Asked Questions

What is benzotriazole UV absorber (UV-328) used for?

UV-328 (CAS 25973-55-1) is a benzotriazole-class ultraviolet light absorber incorporated into plastics, coatings, and adhesives to absorb UV radiation. It has established use in polyolefins, polyurethanes, PVC, polyacrylates, and epoxies, and stabilizes clear/automotive coatings and outdoor articles.

What is the difference between benzotriazole and benzophenone UV absorbers?

Both are UV-absorber classes, but benzotriazoles such as UV-328 generally provide broader UV-band absorption and higher photopermanence in demanding outdoor applications, while benzophenones are often lower cost for less demanding systems. Selection depends on the resin and durability target; specify your polymer on the RFQ.

How does a UV absorber differ from a HALS stabilizer?

A UV absorber like UV-328 works by absorbing incident UV radiation before it degrades the polymer, whereas a hindered amine light stabilizer (HALS) scavenges free radicals formed during degradation. They are frequently used together for additive synergy in coatings and outdoor plastics.

What CAS number and HS code apply to UV-328?

CAS 25973-55-1, molecular formula C22H29N3O. HS classification is 2933.99 (heterocyclic compounds with nitrogen hetero-atom(s) only: other). Request a lot-specific CoA and SDS for assay, identity, and GHS handling data.

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Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.
Regulatory restriction

Sourcing UV-328 (Benzotriazole UV Absorber) requires compliance verification

This substance is subject to regulatory restriction and is not offered for general bulk sale. Contact our team with your jurisdiction of use and compliance documentation.

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