BLS 1326


BLS 1326 (3896-11-5) is a benzotriazole type ultraviolet light absorber (UVA), imparting good light stability for plastics and other organic polymers.  BLS 1326 is especially suited for polyolefins and cold cured polyesters.  It protects polymers from UV radiation helping to preserve the original appearance and physical integrity, especially for polyolefins and polyester resins.


Chemical Name:                        2-(3’-tert-butyl-2’-hydroxy-5’-methylphenyl)-5-


CAS Number:                            3896-11-5

Chemical Structure:

BLS 1326

Typical Properties         

Product Form:                         Solid Melting Point:                          138-141oC

 Molecular Weight:                             315.8 g/mol


BLS 1326 is useful for the light stabilization of plastics, including polyolefins, cold-curing unsaturated polyesters, and others.


  • Strong absorption of ultraviolet radiation in the 300-400 nm region
  • Non-interacting in cold-cured unsaturated polyester systems
  • Good compatibility
  • FDA cleared for use in polyolefins

Guidelines for Use

Typical recommended use levels range between 0.1% and 0.5% in polypropylene, between 0.1% and 0.4% in polyethylene, and between 0.2% and 0.5% in unsaturated polyesters. Combinations with other light stabilizers such as HALS and benzoates often show enhanced performance. The exact formulation to be used is dependent on the substrate, performance requirements, and other factors, and should be determined by the user based on testing to simulate actual conditions of use. Please contact Mayzo for specific recommendations.


This product may be stored up to two years in a sealed container. Containers should be kept tightly closed when not in use and stored in a cool, dry place.


Please consult the Safety Data Sheet (SDS) prior to handling or using this product.

FDA Regulations

BLS 1326 has been cleared for use in olefin polymers under 21 CFR §178.2010. Please contact your Mayzo representative for complete details, including restrictions of use.

Downloadable Product Details:  Please view our BLS 1326 PDF

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