Identity
Ethylhexyl triazone — INCI name Ethylhexyl Triazone, also called octyl triazone, and marketed by BASF as Uvinul T 150 — is a triazine-based organic UVB filter. It was approved in Europe in the mid-1990s and is a mainstay of high-UVB European, Australian and Asian sunscreens.
⚠️ It is a distinct molecule from bemotrizinol (bis-ethylhexyloxyphenol methoxyphenyl triazine, Tinosorb S), which has its own card. Both are triazines, and the similar names are the most common source of confusion in this corner of the filter list — they are not interchangeable.
How it works
Ethylhexyl triazone absorbs in the UVB range with a peak around 314 nm, and it does so with one of the highest extinction coefficients of any UV filter — meaning very high absorbance per unit weight. That efficiency is its signature: it contributes strong UVB protection at low inclusion levels.
Two other properties define it. It is highly photostable — it holds its absorbance under sun exposure rather than degrading like avobenzone or octinoxate — and it is a large molecule (~823 g/mol), which penetrates skin very little and keeps it on the surface where a filter belongs. Well tolerated, with low sensitisation.
Its limitation is spectral, and it is a hard one: ethylhexyl triazone covers UVB and essentially no UVA. It is a specialist, not a broad-spectrum filter, so it is always formulated alongside a UVA filter — avobenzone, bemotrizinol, DHHB or a mineral — to build a complete sunscreen.
Reading the evidence honestly
Why grade A. Within its band, ethylhexyl triazone is first-rate: among the most efficient UVB absorbers available, photostable, very low penetration, well tolerated, and decades of European use. This is the same basis on which DHHB — a UVA-I specialist — earns an A: a single-band filter graded on how well it does its one band, which here is exceptionally.
What the grade does not claim. It is not broad-spectrum and never stands alone; a product is only as good as its whole filter system, and ethylhexyl triazone must be read as one component of it. Its low-penetration profile rests on molecular size and European assessment rather than a US maximal-use plasma study — because it has never been through the FDA process.
The practical story is regulatory. Ethylhexyl triazone has been standard in European and Asian sunscreens for decades while remaining unavailable in the United States, where it is not in the OTC monograph. That is the same gap that kept bemotrizinol out until June 2026 and that DHHB and bisoctrizole still sit behind — an absence of US approval, not an adverse finding. It is part of why American high-UVB formulation has leaned on octinoxate and homosalate instead.
And the constant that outweighs filter choice. As with every filter, real-world protection is governed by how much is applied and how often it is reapplied far more than by which UVB filter a formula uses.