The blacklist: which UV filters are controversial?

Oxybenzone, octinoxate, homosalate, PABA: behind these technical names hide controversial UV filters present in the vast majority of sunscreens sold in pharmacies or supermarkets that Substance of Light® has chosen to exclude from its formulas.

This choice does not stem from a "clean beauty" trend. It is the result of rigorous formulation work: reading studies, weighing available data, and not waiting for a regulatory ban to take action. Our blacklist covers much more than just UV filters: preservatives suspected of being endocrine disruptors, persistent silicones, and ethoxylated compounds, but it is regarding solar filters that scientific questions are currently the most documented.

What is a controversial UV filter?

Chemical filter vs. mineral filter: the basic distinction

There are two main families of UV filters.

Mineral filters : mainly zinc oxide (ZnO) and titanium dioxide (TiO₂), they form a physical shield on the skin's surface. They reflect UV rays without being absorbed by the body.

Chemical filters (or organic filters) absorb UV energy and convert it into heat. Unlike mineral filters, they interact with the surface layers of the skin to accomplish this conversion.

Why are some filters debated?

A filter becomes "controversial" when scientific studies raise questions about its safety: detection in the blood after normal application, potential interaction with the endocrine system, or accumulation in tissues or the marine environment.

This is not a matter of alarmism, it is a matter of precaution, anchored in peer-reviewed scientific publications; serious enough that European health authorities have already reduced the authorized concentrations of several filters.

It is on this basis that we have built our list of ingredients to avoid in our sun care formulas.

The most documented controversial UV filters

Here are the eight UV filters we have excluded from our formulas, with the scientific reasons behind each decision.

Oxybenzone: the most cited endocrine disruptor

Oxybenzone is probably the most studied and most criticized UV filter. A study published in the Journal of the American Medical Association in 2020 (Matta et al., 2020) demonstrated that after a single application over a large skin area, it enters the bloodstream. Detectable levels have been found in blood, urine, breast milk, and amniotic fluid.

What concerns researchers is its potential estrogenic activity: its ability to mimic female hormones and interfere with the endocrine system. When it comes to endocrine disruptors in sunscreen, oxybenzone is systematically the first name cited in international scientific reports.

It is currently under active surveillance by the Scientific Committee on Consumer Safety (SCCS) at the European level.

Octinoxate: skin absorption and hormonal effects

The second most used chemical filter in the world, octinoxate is subject to increased scientific monitoring. In vitro and animal studies have highlighted weak but measurable estrogenic activity (SCCS, Opinion on Ethylhexyl Methoxycinnamate, 2021).

Octinoxate is also noted for its photochemical instability: when exposed to UV, it degrades and can generate potentially irritating derivatives, which also reduces the effectiveness of the protection over time.

Note: Hawaii and several U.S. states have banned it in sun care products, due to its documented impact on coral reefs.

Homosalate, Octisalate, Octocrylene: the trio to watch

These three filters are among the most widespread in conventional sun care formulas. Their toxicological profiles raise growing questions, documented by the SCCS.

 

Octocrylene deserves special attention. Its degradation into benzophenone, a substance classified as potentially carcinogenic, is now well documented, whether during storage or solar exposure.

PABA and TiO₂ in nanoparticles: the other exclusions

PABA (para-aminobenzoic acid) is one of the first UV filters used in cosmetics. Gradually abandoned by the industry, it remains present in some formulas despite its high potential for causing allergies and its ability to trigger photoallergies, even at low concentrations.

Titanium dioxide in nanoparticles is a special case. Classic TiO₂ is a well-tolerated mineral filter; it is its nanometric form that raises questions. These particles are small enough to potentially cross the skin barrier, with biological behavior that is not yet sufficiently documented. As a precaution, we exclude it from our formulas.

What does European regulation say?

The European Union has one of the strictest regulatory frameworks in the world for cosmetics. But "authorized" does not mean "free of scientific questioning."

The SCCS regularly reassesses UV filters as studies accumulate. Several have seen their maximum authorized concentration reduced in recent years, proof that concerns are being taken seriously, even if a total withdrawal has not yet been enacted.

At Substance of Light®, we don't wait for a ban to act. We apply our own standard, more demanding than current regulations, and our formulation approach is detailed on our TRUE FILTER™ page.

Endocrine disruptors and sunscreen: what we really know

The concept of endocrine disruptors in sun protection is often misunderstood, either downplayed or sensationalized.

What studies show on systemic absorption

The question is no longer whether certain chemical UV filters cross the skin. We now know that they do, for several of them. The real question is: once in the bloodstream, what do they do?

Published studies show that oxybenzone, octinoxate, and homosalate are detected in blood plasma after application under normal conditions of use. Absorption increases with the area of exposed skin, the frequency of application, and body temperature. Yet some of these molecules have the ability to bind to hormone receptors—estrogen, androgen—and mimic or disrupt their functioning. It is this precise mechanism that is at the heart of current scientific concerns.

The populations most exposed to risks

Children first: Their skin barrier is more permeable than that of adults, meaning a larger proportion of applied filters enters the body. But it is especially the timing of exposure that matters: during childhood and puberty, the hormonal system is under construction. Interference at this stage, even if weak, can have consequences different from those observed in an adult whose endocrine system is stabilized.

Pregnant women next: Prenatal exposure to endocrine disruptors is particularly monitored by researchers: some molecules cross the placental barrier and can reach the fetus at a stage when its hormonal systems are being established. This is precisely why most health organizations recommend limiting any unnecessary exposure during pregnancy (WHO, Endocrine Disruptors, 2023).

For these two profiles, the choice of a well-formulated sunscreen is not an anecdotal issue.

Why these ingredients are on the Substance of Light® blacklist

At Substance of Light®, we did not just exclude controversial UV filters. Our blacklist covers the entire formula: preservatives suspected of being endocrine disruptors, silicones that are persistent in the environment, ethoxylated compounds, mineral oils, synthetic fragrances, and allergens.

The criteria that guide every decision are always the same: are we comfortable with this ingredient? Can we recommend it without reservation, including for sensitive skin, a child, or a pregnant woman?

For the eight UV filters listed in this article, the answer is no. Find the full list of excluded ingredients on our blacklist page; each exclusion is justified there, not as a marketing argument, but as a documented formulation commitment. A transparency that you can also find on our Our Results page.

What we use instead: the filters in the TRUE FILTER™ formula

Excluding is not enough. You must replace them with alternatives that ensure real UV protection, without the shadow areas of controversial filters.

The TRUE FILTER™ formula is based on new-generation UV filters, selected for their photostable effectiveness and solid safety profile:

• Filmexel : photostable organic filter, absent from all international watch lists
• Tinosorb S & Tinosorb M : new-generation filters with high skin tolerance, covering UVA and UVB with stability over time
• Non-nano Zinc Oxide (ZnO) : broad-spectrum coverage, without systemic penetration, without the questions related to nanoparticles
  

These filters are not a compromise on protection; they are the achievement of it. You can find them in the Urban Protective Mist, our light protection that is re-applicable over makeup, and in the Protective Moisturizing Fluid for maximum daily protection.

By choosing UV filters recognized for their stability, effectiveness, and excellent tolerance, the TRUE FILTER™ formula meets a simple requirement: offering high-performance sun protection without relying on ingredients that are currently the subject of scientific or environmental controversy. Because effective sun protection should never force you to choose between safety, comfort, and performance, we have designed a formula that brings these three criteria together within the same approach.

 

 

FAQ — Controversial UV filters: your questions

Is oxybenzone banned in France? No. Oxybenzone is still authorized in the European Union. At Substance of Light®, we have chosen to exclude it independently of this authorization, applying our own precautionary criterion.

Is a chemical filter necessarily dangerous?No. The "chemical filter" category includes very different molecules; some are debated, while others have a solid safety profile and do not appear on any watch list. The Tinosorb S, Tinosorb M, and Filmexel® filters that we use in TRUE FILTER™ are a good example: new-generation organic filters that are effective, photostable, and well-documented from a toxicological standpoint.

How do I know if my sunscreen contains endocrine disruptors? Applications like INCI Beauty allow you to scan a product and instantly identify ingredients under surveillance.

Bibliography

• Matta, M.K. et al. (2020). Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients. Journal of the American Medical Association. https://jamanetwork.com/journals/jama/fullarticle/2759002
• SCCS Scientific Committee on Consumer Safety (2021). Opinion on Ethylhexyl Methoxycinnamate https://health.ec.europa.eu/publications/sccs-opinion-ethylhexyl-methoxycinnamate-ehmc-cas-no-5466-77-383834-59-7-ec-no-226-775-7629-661-9_en
• SCCS Scientific Committee on Consumer Safety (2021). Opinion on Titanium Dioxide https://health.ec.europa.eu/system/files/2021-11/sccs_o_238.pdf
• Gonçalo, M. et al. (1995). Photoallergic contact dermatitis from sunscreens containing PABA derivatives. https://pubmed.ncbi.nlm.nih.gov/29655482/