Boron Oxide
AKA “Boron sesquioxide, Boron Oxydatum, Fused boric acid, Caswell No. 109B, Boric oxide (B2O3), RefChem:917472, Boric acid (HBO2), anhydride”
Ingredient Facts
Boron oxide
AKA: Boron sesquioxide, Boron Oxydatum, Fused boric acid, Caswell No. 109B, Boric oxide (B2O3), RefChem:917472, Boric acid (HBO2), Anhydride
Synthetic · Buffering · EWG: 3
Synthetic
Clean
A subtle fragrance ingredient that adds a delicate scent profile to beauty products.
Solubility 3 % (NIOSH, 2024)
Formula
B2O3
Mol. Weight
69.63
Form
Powder
State
Boron oxide appears as colorless, semi-transparent glassy lumps or hard white odorless crystals. Mp 450 °C; bp: 1860 °C. Density: 2.46 g cm-3. Moderately soluble in water. Used as an insecticide; as t
See origin →
Functions
Buffering
Viscosity Controlling
Provides scent
Traditional Use
This is a laboratory reagent classification, not a cosmetic ingredient.
Skin Types
●all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Safety Assessment of Trimellitic Anhydride Copolymers as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Adipic Acid/CHDM/MA/Neopentyl Glycol/Trimellitic Anhydride Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Isostearoyl Trimellitic Anhydride/Trimethylolpropane Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Phthalic Anhydride/Trimellitic Anhydride/Glycols Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Trimethylpentanediol/Isophthalic Acid/Trimellitic Anhydride Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Boron Oxide
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Phthalic Anhydride/Trimellitic Anhydride/Glycols Copolymer
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride.
Li C, Tian Z, Liu W, Li G
Materials science & engineering. C, Materials for biological applications, 2015
Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR