Identity
Bemotrizinol — INCI name bis-ethylhexyloxyphenol methoxyphenyl triazine, abbreviated BEMT, and sold as Tinosorb S (BASF), Parsol Shield (DSM) and Escalol S — is an oil-soluble, triazine-based organic UV filter. It was developed by Ciba Specialty Chemicals, later acquired by BASF.
⚠️ Do not confuse with bisoctrizole (Tinosorb M) — a different filter with a nearly identical trade name. The two are often mentioned together and are not interchangeable.
A note on why this entry exists now: for most of its life, bemotrizinol was the standard example of the gap between European and American sun care — widely used abroad since around 1999-2000, unavailable in the US. That changed in June 2026.
How it works
Bemotrizinol absorbs across the full ultraviolet range through two absorption peaks, at approximately 310 nm and 340 nm. That dual-peak profile is what makes it broad-spectrum in a single molecule: 310 nm sits in UVB, 340 nm in UVA, and the absorption band is wide enough to bridge them and extend into long UVA.
Its second defining property is photostability. Where avobenzone loses much of its UVA absorbance within an hour of sun exposure through tautomerisation, bemotrizinol retains 98.4% intact after 50 minimal erythemal doses — an exposure far beyond a normal day outdoors. It does not merely survive UV; it can absorb the energy that would otherwise degrade neighbouring filters, which is why it doubles as a photostabiliser for avobenzone and octinoxate.
Its molecular size (around 628 g/mol) is also relevant: large molecules cross the stratum corneum poorly, which is the likely explanation for its very low systemic absorption.
The 2026 US approval, and what it actually means
In June 2026, the FDA finalised Administrative Order OTC000039, adding bemotrizinol to the OTC Sunscreen Monograph M020 as a GRASE ingredient at up to 6%, for ages 6 months and older (published in the Federal Register on 10 June 2026, effective 9 August 2026; the proposed order was issued in December 2025). It is the first new sunscreen active added to the US monograph since the late 1990s. Bemotrizinol had been available abroad for over two decades and pending in the US since the early Time-and-Extent-Application era — the 2026 order came through a manufacturer request under the newer CARES Act pathway.
Three implications worth separating.
For US formulation. American formulators have been working with a short filter list, in which avobenzone was effectively the only widely used long-UVA organic option and octocrylene the main way to keep it stable. Bemotrizinol adds a filter that is broad-spectrum, photostable, and itself a stabiliser. Dermatology commentary frames the likely result as lighter, more wearable US sunscreens — which matters less as luxury than as adherence, since the sunscreen people actually wear outperforms the one they avoid.
For the "mineral vs chemical" framing. This approval quietly dismantles a common marketing shorthand. The claim that mineral filters are GRASE and chemical filters are not was always a description of data submitted, not of safety established — and bemotrizinol is now an organic filter with full GRASE standing. The distinction was regulatory history, not chemistry.
A practical caution. Existing European formulas cannot simply be relabelled for the US market: permitted concentrations, the surrounding filter system and monograph requirements differ. Expect US products containing bemotrizinol to appear gradually rather than immediately, and expect the same product name to carry different filter systems in different markets — always check the actual ingredient list of the version you are buying.
Reading the evidence honestly
Bemotrizinol earns grade A, which in this register is uncommon, so it is worth being precise about why — and about what an A does not mean.
What is genuinely strong. Full-range coverage from one molecule; quantified photostability (98.4% after 50 MEDs) that is exceptional rather than merely adequate; documented ability to preserve other filters, reportedly up to 100% of avobenzone in some combinations; minimal systemic absorption, with only 13 of 299 plasma samples quantifiable in a maximal-use trial of a 6% formulation; low irritation rates in the FDA's review; and more than two decades of real-world use across Europe, Australia and Asia before US approval.
What an A does not mean. It does not mean bemotrizinol is necessary — well-formulated sunscreens without it protect perfectly well, and zinc oxide covers a similar spectrum. It does not make older filters unsafe; avobenzone with proper stabilisation remains effective, and the FDA's absorption findings for organic filters have not been shown to correspond to harm. And it does not change the fundamentals: the amount applied and the frequency of reapplication determine real-world protection more than the choice of filter. Most people apply well under the quantity used in SPF testing, and no filter compensates for that.
One honest limitation of this entry. The US approval is very recent. American product availability, real-world formulation choices and any post-approval findings are still developing.