Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (MBBT, CAS 103597 45-1) is an official UV filter reported in Annex VI, Entry 23 of the European Cosmetics Regulation. As of today, this ingredient can be used at up to 10% in its normal form.

Until now, the nano-form of this material could also be used but only by complying with Article 16, which foresees a special CPNP notification of the nanomaterial six month prior placing on the market a product that containsit. This new piece of legislation (EU No 2018/885) makesthis process obsolete for MBBT and the use of its nano-form becomes significantly easier.

The use of the normal form of MBBT remains allowed at 10% (Entry 23) and no specific purity criteria apply. The use of the nano-form of MBBT is allowed at 10% too (Entry 23a) butspecific purity criteria have to be fulfilled:

• Not to be used in applications that may lead to exposure of the end user’s lungs by inhalation.
• Only nanomaterials having the following characteristics are allowed:
  • Purity ≥ 98,5 %, with the isomer fraction not exceeding 1,5 % and with the following impurity profile: water < 0,1 %; Cr, Cu, Fe, Na, Pb, Sb, Se, Sn or Zn < 10 mg/kg; As or Cd < 5 mg/kg; Ni < 3 mg; Hg < 1 mg/kg; Isopropanol ≤ 2,2 μg/g; Dibutylamine < 0,5 μg/g; Xylene (mixture of ortho-, meta- and para- isomers) ≤ 6,8 μg/g; Formaldehyde ≤ 0,93 μg/g;
  • Solubility < 5 ng/L in water at 25 °C;
  • Zeta-potential: -25 mV at pH 7;
  • Partition coefficient (Log Pow): 12,7 at 25 °C;
  • Uncoated;
  • Median particle size D50 (50 % of the number below this diameter): ≥ 120 nm of mass distribution and/or ≥ 60 nm of number size distribution.

Furthermore, the regulator specifies that “In case of combined use of Methylene Bis-Benzotriazolyl Tetramethylbutylphenol and Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (nano), the sum shall not exceed the limit of 10%.” This new Regulation will get implemented 20 days after its publication in the Official Journal of the European Union, namely on July 10th, 2018.