Methylene Bis-Benzotriazolyl Tetramethylbutylphenol Best UV filter Anti-Ageing Methylene Bis-Benzotriazolyl Tetramethylbutylphenol at a glance Synthetic broad-spectrum UV filter that helps defend skin against UVA and UVB rays Unique in that its mechanism of action is a hybrid of a chemical and physical protection Also used to stabilize other ingredients and prevent formulary deterioration Approved as UV filter in many global markets but not in the U.S. Also goes by Tinosorb M or Bisoctrizole Methylene Bis-Benzotriazolyl Tetramethylbutylphenol description Methylene bis-benzotriazolyl tetramethylbutylphenol is a synthetic broad-spectrum UV filter that helps defend skin against UVA and UVB rays with peak protection at 305 nm within the UVB range and 360 nm within the UVA range. In this regard, it can also be considered an anti-aging ingredient as it helps prevent accelerated signs of aging triggered by sun exposure. Methylene bis-benzotriazolyl tetramethylbutylphenol is unique in that researchers describe its mechanism of action as a hybrid of a chemical + physical sun protection. A portion of the molecule is microfine pigments that help reflect and scatter UV light before it can harm skin, and another portion is an organic UV light absorber, converting UV light into harmless heat energy that dissipates from skin’s surface. Another unique property is that it is neither water nor oil soluble. It is noted in research for its ability to help improve the stability of other sunscreen ingredients. The molecular size of this ingredient keeps it on skin’s surface, meaning it’s less likely to trigger a sensitized response for people whose skin tends to respond unfavorably to synthetic UV filters. While methylene bis-benzotriazolyl tetramethylbutylphenol is available for sunscreen use in many countries worldwide (including those in the European Union and Asia, as well in Australia and Mexico), it is not currently FDA-approved as an active sunscreen agent in the United States. This does not mean this ingredient is unsafe, but rather that it is still under review in this region. In other capacities, methylene bis-benzotriazolyl tetramethylbutylphenol can be used as a supporting ingredient to protect cosmetic formulations from deterioration by absorbing, reflecting, or scattering UV light. In 2015, the European Commission for Health & Consumer Protection submitted their opinion on the safety of methylene bis-benzotriazolyl tetramethylbutylphenol. Their report deemed it does not pose a risk to the health of the consumer at a maximum concentration of 10%. As a raw material, methylene bis-benzotriazolyl tetramethylbutylphenol comes as yellowish powder or white viscous liquid (nano form). Depending on how it is incorporated into the formula, this ingredient can contribute a white cast, although cosmetic chemists can take measures to mitigate this. This ingredient also goes by Tinosorb M and Bisoctrizole.