# Tinosorb M (bisoctrizole) Source: https://theconstantbeauty.com/ingredients/methylene-bis-benzotriazolyl-tetramethylbutylphenol/ Retrieved for: theconstantbeauty.com Publisher: The Constant (theconstantbeauty.com). Cite as "The Constant". Generated: 2026-09-16T18:19Z - **INCI name:** Methylene Bis-Benzotriazolyl Tetramethylbutylphenol - **Common name:** Tinosorb M (bisoctrizole) - **Typical use range:** Up to 10% (EU Annex VI) - **Evidence tier:** literature-backed - **Functions:** uv-filter ## What it does Methylene bis-benzotriazolyl tetramethylbutylphenol, sold as Tinosorb M and known generically as bisoctrizole, is an unusual filter. It is an organic molecule, but it is supplied as micro-fine particles dispersed in water rather than dissolved in oil. That gives it a hybrid action: the particles absorb UV like an organic filter and also scatter and reflect it like a mineral one. Coverage is broad, spanning UVB and UVA with a strong contribution around 360 nm, and it is highly photostable. Because it sits in the water phase it lets a formulator add protection without loading the oil phase, which keeps textures lighter. It also helps stabilise other filters in the formula. It is listed in Annex VI of the EU Cosmetics Regulation at up to 10%, including in nano form, which has been assessed by the EU Scientific Committee on Consumer Safety. On a label it often appears alongside the dispersion aids it arrives with, such as decyl glucoside and propylene glycol. ## Notes Methylene bis-benzotriazolyl tetramethylbutylphenol, sold as Tinosorb M and known generically as bisoctrizole, is an unusual filter. It is an organic molecule, but it is supplied as micro-fine particles dispersed in water rather than dissolved in oil. That gives it a hybrid action: the particles absorb UV like an organic filter and also scatter and reflect it like a mineral one. Coverage is broad, spanning UVB and UVA with a strong contribution around 360 nm, and it is highly photostable. Because it sits in the water phase it lets a formulator add protection without loading the oil phase, which keeps textures lighter. It also helps stabilise other filters in the formula. It is listed in Annex VI of the EU Cosmetics Regulation at up to 10%, including in nano form, which has been assessed by the EU Scientific Committee on Consumer Safety. On a label it often appears alongside the dispersion aids it arrives with, such as decyl glucoside and propylene glycol. ## Used in - [Silk Veil SPF 50+ PA++++ Sunscreen](https://theconstantbeauty.com/product/silk-veil-spf-50-sunscreen/) ## References 1. CosIng, Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (EU cosmetic ingredient database) 2. Regulation (EC) No 1223/2009 on cosmetic products, Annex VI (UV filters allowed in cosmetic products). 3. Scientific Committee on Consumer Safety (SCCS). Opinion on 2,2'-methylene-bis-(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol) (nano), SCCS/1546/15.