March 19, 2018
I protect you from the European sun, but not from American rays.
What molecule am I?
Image of Bisoctrizole 3D Image of Bisoctrizole

The two benzotriazole groups in bisoctrizole make it an ideal substance for absorbing ultraviolet radiation. Thus, it is produced by BASF (Ludwigshafen, Germany) and MPI Chemie (Houten, The Netherlands) as an additive for sunscreen formulations.

Most compounds used in sunscreens are dissolved in the organic or aqueous phase of the product. But bisoctrizole is almost insoluble in anything, so it is prepared in microfine particles that are suspended in the aqueous phase.

Bisoctrizole is approved for use in the European Union and elsewhere, but not in the United States. The reason is that the manufacturers of bisoctrizole and other sunscreen ingredients are in a stalemate with the US Food and Drug Administration. FDA has requested additional toxicity data for the products to comply with current regulations, but the producers, citing the cost of testing, have asked FDA to relax the standards. As of January 2018, the situation had not been resolved.

Bisoctrizole hazard information

GHS classification*: hazardous to the aquatic environment, acute hazard, category 3
H402—Harmful to aquatic life Chemical Safety Warning
GHS classification: chronic aquatic toxicity, category 4
H413—May cause long-lasting harmful effects to aquatic life

*Globally Harmonized System of Classification and Labeling of Chemicals. Explanation of pictograms.

Bisoctrizole fast facts

CAS Reg. No.103597-45-1
Molar mass658.88 g/mol 
Empirical formulaC41H50N6O2
AppearanceWhite powder
Melting point197–200 °C
Water solubilityInsoluble
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