What makes a good UV filter?

Not all UV filters are equally good. There are UV filters that disintegrate under UV radiation, i.e. are not photostable. This reduces the protective effect and the decay products can irritate the skin.

Some chemical sunscreen filters can cause allergies. This reaction is often interpreted as a sun allergy even though the skin is reacting to the sunscreen. We find it particularly worrying if UV filters contain nano-particles and can penetrate the skin due to their small molecular size and get into the bloodstream. The result, an increased risk that they will disrupt the body’s metabolic processes. That is why it is important to look closely at UV filters.

So what properties will a  good UV filter have? We believe the following are vital:

  • Do not penetrate the skin
  • Do not cause allergies
  • Be photostable, i.e. not decay in the sun
  • Have no side effects on the body’s metabolism

Sun protection: what to look for when buying

The UV filters are listed with the other ingredients on the packaging of the sunscreen. However, the manufacturers usually combine several UV filters in one product. In addition, many filter substances are hidden behind complicated and difficult to remember names (see list at the end). So we have to take a closer look. And we hope that the EU Cosmetics Regulation will change the regulations here that manufacturers need to list them separately to make it crystal clear and empower the consumer. As it is tedious, but so worth taking a close look at the list of ingredients.

Important: protection against UVA and UVB radiation

The sun filter combination should protect against both UVA and UVB rays. The sun’s UVB rays trigger sunburn, while UVA rays contribute to skin ageing by damaging the DNA within the skin.

The specified sun protection factor (SPF) only relates to UVB radiation. It is therefore important that the UVA symbol is also shown on the packaging. This is the only way to be sure that the product protects against both rays.

The seal is issued if the UVA protection is ⅓ of the UVB protection. With sun protection factor 30, the UVA factor must be at least 10. Incidentally, the UVA factor is also called PPD. This stands for Persistent Pigment Darkening. So it’s about protecting against pigmentation, i.e. tanning the skin. Of course there is a cost associated to this to get this approved which is more than 2000 euros per product. However, as a consumer it will be a clear guide to which product to invest in and which product to ditch.

From a dermatological point of view, the higher the UVA protection, the better. If in doubt, ask your manufacturer.

Chemical, organic or mineral? The types of UV filters

To protect the skin from UV radiation, there are 2 different types of UV filters. Chemical filters convert the UV rays on the skin into heat. Mineral filters reflect sunlight on the skin. Mineral filters are small particles of zinc or titanium dioxide. (See image below)

Chemical filters are also known as organic filters. Mineral filters can also be called inorganic or physical UV filters.

Both filters have advantages and disadvantages. Let’s take a closer look at the mineral filters.

Mineral filters: safe and compatible

Mineral filters such as titanium dioxide or zinc oxide (INCI: Titanium Dioxide, Zinc Oxide) are generally compatible. They have the advantage that they do not disintegrate and do not cause allergic reactions. Incidentally, certified natural cosmetics must always be limited to mineral filters.

However, these filters are not as pleasant to use as the chemical alternatives. The small particles often leave a white haze on the skin and are difficult to remove. Thus, it is particular vital to clean the skin thoroughly to remove the trace of the product from your skin.

Mineral nano-size filters: harmful or not?

This is remedied by nano-sized mineral particles. These are tiny and are therefore easier to spread over the skin. Recently, however, there has been a discussion about these small particles. It is believed that the particles are so small that they penetrate the body. There they could endanger the organism.

According to the current study situation, it has not been finally clarified whether nanoparticles penetrate the skin. In this article, we look at how harmful nanoparticles in sunscreens really are.

If you want to be on the safe side, you should avoid nanoparticles. In our opinion, this applies above all to special children’s and baby sun creams. The baby skin is so tender that you shouldn’t take any risks.

By the way, all particles in nano size must be labeled with the word “nano” (always in brackets after the respective filter).

Which is better: chemical or mineral filters?

While mineral filters are always compatible, you have to look very closely at chemical UV filters.

A look at the list of ingredients can be worthwhile. Because a sunscreen with compatible chemical filters is just as harmless as a mineral sunscreen.

There are even some advantages. Modern chemical filters are much easier to remove from the surface of the skin because they do not penetrate the skin. Mineral filters remain on the skin longer and can accumulate in our horny layer. This means that mineral sun protection products can dry out the skin.

The right chemical UV filters are better

After intensive work with the UV filters used, we are now of the opinion that sunscreens with the right chemical filters are better.

But be careful: there are many chemical sun protection filters with undesirable side effects. Unfortunately, these are also the filter materials that are used most frequently, e.g. Octocrylene.

Natural UV filters – is there such a thing?

We answer this question with a clear yes and no. Mineral filters could be considered natural UV filters. However, they have dermatological disadvantages (drying out the skin).

Tiny zinc oxide and titanium particles have no place in our ecosystem either. So they are not really natural

Are organic UV filters natural?

Chemical UV filters are also called organic filters. But is that why they are natural?

Not really. Although they are organic compounds, they are substances that do not occur naturally in nature. Some have side effects.

Antioxidants and oils as natural UV filters?

Many antioxidants, such as B. Vitamin E and Vitamin C, help the skin protect itself against UV radiation. Herbal substances such as green tea, resveratrol or astaxanthin also protect our skin. These substances offer natural sun protection.

But be careful: the natural sun protection factor is very low. Nobody should only rely on natural substances. We recommend that you always use “real” UV filters.

Which chemical UV filters are harmless?

There are now a whole range of chemical UV filters that provide compatible protection against UV radiation. According to the current state of research, these UV filters are harmless. The allergizing potential is low and studies have not shown any hormonal effects. Of course, all of the filters listed here are also photostable.

We avoid these UV filters

All common UV filters were classified as “safe” on the positive list of the Cosmetics Regulation. Nevertheless, new studies are published again and again and we don’t have the “average skin” in mind, but our own and that of our family. That is why we consolidated the list below that we would never include in our products if we were to develop a Sun Protection Lotion.

These UV filters penetrate the skin:

We believe that chemical UV filters have lost nothing in the body and should not be deposited there. Various studies have made it possible to conclude whether the skin lets the substances through or not.

Studies are regularly conducted in which either the blood or breast milk of test persons is tested for certain chemicals. If the UV filters are detected, this means that they have somehow entered the body.

There are also laboratory tests that examine the rate of penetration through the skin. For the UV filter Benzophenone-3 z. B. found a penetration rate of over one percent. Other UV filters that fail this test are:
Benzophenone-3, Benzophenone-4, Benzophenone-5, 4-Methylbenzylidene Camphor, Homosalate, Octocrylene, Octyl Methoxycinnamate

These UV filters trigger allergies:

Some of the UV filters have been reported to trigger allergic reactions. Incidentally, this can also be the cause of a supposed sun allergy. We recommend avoiding the potential allergens:
Benzophenone-3, Benzophenone-4, Benzophenone-5, Ethylhexyl Dimethyl PABA, Homosalate, Octocrylene

These UV filters are suspected of disrupting metabolic processes:

This can happen if UV filters are similar to our hormones. Then they interfere with various metabolic processes or could favor tumors. So why use these fabrics when there are better ones? We do without:
Benzophenone-3, Benzophenone-4, Benzophenone-5, 4-Methylbenzylidene Camphor, Isoamyl Methoxycinnamate, Homosalate, Octocrylene, Octyl Methoxycinnamate

These UV filters are not photostable:

A substance that is supposed to protect us from the sun should not disintegrate under the sun’s rays. There are ways to stabilize these UV filters with other ingredients, but caution is also required with these:
Octyl methoxycinnamate

These UV filters contain microplastics:

Tinosorb S is a safe UV filter that we recommend. But there is also the new filter Tinosorb S Lite Aqua. (INCI: bis-ethylhexyloxyphenol methoxyphenyl triazine, acrylates / C12-22 alkyl methacrylate copolymer). Here the oil-soluble filters were encapsulated with microplastics. This way, lighter textures can be created. We do not recommend microplastics for ecological reasons.

Chemical-mineral mixed forms with nanoparticles:

The Tinosorb M and Tinosorb A2B (INCI: Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) and Tris-Biphenyl Triazine (Nano)) filters are novel mixed forms of filters. They are both chemical and mineral. Since these filters rely on nanoparticles, we cannot fully recommend them.

Which sunscreen is coral friendly?

Something not new that unfortunately, some of the UV filters that might protect us, damage our nature – ultimately the coral reefs. The filters that have been are continue to be criticized are the 3 Os: Oxybenzone, Octocrylene, and Octinoxate.

The use of Oxybenzone and Octinoxate is even banned in Hawaii. Octocrylene can be found in most products on the German market – and in high concentration. We recommend that you do not use these filters.

There is also a new UV filter which we already mentioned above that contains microplastics: Tinosorb S Lite Aqua. We do not recommend this filter to protect our oceans.

There are many uncertainties in the ‘Reef Safe’ discussion. Not all filters have been examined. The common belief is that mineral filters such as zinc oxide and titanium dioxide are reef friendly. However, there are also dissenting votes.

Conclusion

This is one of the most confusing spaces when it comes to the beauty space. Even though there are many more. The variety of UV filters is difficult to see through and often several are combined in one sunscreen. Making it hard to understand which one to use and which one to avoid. But if you look closely, you can take a big step towards compatible sun protection.

If you want to do without chemistry, you should use mineral filters such as zinc oxides and titanium dioxide. However, there are also chemical alternatives that are also harmless and have advantages.

During the Sun Awareness Week, we will consolidate a list with common UV Filters. So nothing stands in the way of your safe sunbathing. PLUS, we can safely say that the harmless UV filters from our list also minimize the risk to our oceans.


Reference

EWG – https://www.ewg.org/sunscreen/report/nanoparticles-in-sunscreen/

de Groot AC1Roberts DW., “Contact and photocontact allergy to octocrylene: a review.”, Available online: https://www.ncbi.nlm.nih.gov/pubmed/24628344

Brian Gulson, Maxine McCall, Michael Korsch, Laura Gomez,Philip Casey, Yalchin Oytam, Alan Taylor, Malcolm McCulloch,Julie Trotter, Leslie Kinsley, “Small Amounts of Zinc from Zinc Oxide Particles in Sunscreens Applied Outdoors Are Absorbed through Human Skin”, Toxicological Sciences, Volume 118, Issue 1, November 2010, Pages 140–149, https://doi.org/10.1093/toxsci/kfq243 . Available online: https://academic.oup.com/toxsci/article/118/1/140/1664509

Gustavsson Gonzalez H1Farbrot ALarkö O., “Percutaneous absorption of benzophenone-3, a common component of topical sunscreens.”, Available online: https://www.ncbi.nlm.nih.gov/pubmed/12472548

Grether-Beck S1Marini AJaenicke TKrutmann J., “Effective photoprotection of human skin against infrared A radiation by topically applied antioxidants: results from a vehicle controlled, double-blind, randomized study.”, Available online: https://www.ncbi.nlm.nih.gov/pubmed/25349107

Baroli B1Ennas MGLoffredo FIsola MPinna RLópez-Quintela MA., “Penetration of metallic nanoparticles in human full-thickness skin.”, Available online: https://www.ncbi.nlm.nih.gov/pubmed/17380118

de Groot AC1Roberts DW., “Contact and photocontact allergy to octocrylene: a review.”, Available online: https://www.ncbi.nlm.nih.gov/pubmed/24628344

Avenel-Audran M1Dutartre HGoossens AJeanmougin MComte CBernier CBenkalfate LMichel MFerrier-Lebouëdec MCVigan MBourrain JLOuttas OPeyron JLMartin L., “Octocrylene, an emerging photoallergen.”, Available online: https://www.ncbi.nlm.nih.gov/pubmed/20644036

Chatelain E1Gabard B., “Photostabilization of butyl methoxydibenzoylmethane (Avobenzone) and ethylhexyl methoxycinnamate by bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), a new UV broadband filter.” Available online: https://www.ncbi.nlm.nih.gov/pubmed/11594052