UV filters: chemical vs. mineral

Sun protection – a topic that affects our skin and our health, but sadly one that often gets underestimated. Because sun protection isn't just a beauty trend, it's essential protection for our largest organ.

Along with warmth, the sun also gives off ultraviolet (UV) rays that we can't see and can't sense with any other sense organ either. UV radiation is carcinogenic and has negative health effects on our skin and eyes. These can show up immediately, i.e. acutely and short-term, in the form of sunburn, eye inflammation and allergic reactions, or they can bring long-term effects with them. Among the most serious long-term consequences are various skin cancers. The number of skin cancer cases in Germany has more than doubled since 2000, so it keeps climbing. Besides skin cancer, UV radiation can over the long term also lead to cataracts or other eye diseases and age the skin prematurely. That then shows not just as wrinkles, but also as slower wound healing. To avoid skin damage from UV radiation, you should steer clear of strong UV rays and dress sensibly. Uncovered skin should be protected with sunscreen .

Today it's all about sun protection – more precisely, about the two most common UV filters: the organic, also called chemical, filter and the inorganic one, better known as mineral.

What is a mineral sunscreen?

Mineral sun protection is entirely of natural origin in the form of minerals – such as titanium oxide and zinc oxide. They form a protective film on the skin that reflects and scatters UV rays – much like a mirror. Mineral filters are effective immediately after applying and don't get in the way of the body's own vitamin D production. On top of that, they're also tolerated by children's skin and sensitive skin.

At higher sun protection factors, a white film appears on the skin after applying. Some brands of natural-cosmetics sunscreens respond to this issue by shrinking the minerals to nano size. That makes the creams easier to spread, gives high UV protection and leaves no white film. The catch: because of their tiny size, they're not entirely uncontroversial. They're suspected of penetrating the skin and then getting into the body. Their effect on the body hasn't been researched enough yet. Studies have shown, though, that inhaling nano titanium oxide can lead to lung inflammation. That's why sunscreen sprays with nano titanium oxide in particular are concerning, because spraying makes you more likely to breathe in the mineral at nano size than in cream form. The impact of nanoparticles on the environment unfortunately hasn't been researched enough yet. Nanoparticles from zinc oxide, however, are said to harm and bleach corals on direct contact through zinc-ion formation and physical damage. To limit radical formation, the nanoparticles are often coated with silicon oxide, magnesium or aluminium, but that doesn't help against coral damage on direct contact.

Larger particles of zinc and titanium oxide, however, are largely UV filters that are neutral for the environment and the skin. That's why our mineral organic sunscreens contain no nanoparticles.

What is a chemical sunscreen?

Chemical sun protection is of synthetic origin and has to penetrate the epidermis – the uppermost layers of our skin in order to work. Our skin is then protected from UV damage by absorbing the UV rays and converting them into (harmless) heat. That's also why the protective effect only kicks in 15–30 minutes after applying. To cover the entire UV spectrum, a combination of several synthetic active ingredients is needed.

Some chemical filters, above all benzophenone-3 or EHMC (ethylhexyl methoxycinnamate), are hormonally active chemicals, EDCs (endocrine disrupting chemicals) for short, so they can trigger biochemical reactions in various parts of the human body. A Danish study in 2016 showed that some chemical UV filters have negative effects on human sperm, because they act similarly to the hormone progesterone. On top of that, some chemical active ingredients are suspected of being carcinogenic. The overall damage potential of the chemicals that have penetrated the body unfortunately hasn't been researched enough yet.

In early 2021, the US state of Hawaii banned sunscreen containing the chemical filters octinoxate and oxybenzone to protect the ocean. In Germany these substances are still allowed, but more and more sunscreen makers are advertising “reef-friendly” sun protection that no longer contains these two chemicals.

But other chemical UV filters have a negative impact on the environment too – especially underwater: a study by the US National Oceanic and Atmospheric Administration found that numerous chemicals from sunscreen harm the underwater world. These chemicals encourage the bleaching and even death of corals, infertility in fish and impairments in the growth and photosynthesis performance of green algae. They also affect the hormone balance of many marine animals, though the consequences of that are still unclear.

Advantages of chemical sun protection

Broad protection: Some chemical filters offer broad protection against both kinds of UV rays: UVA and UVB.

Easier to apply: Because of their mostly liquid texture, chemical sunscreens spread better on the skin. So you also need smaller amounts to protect larger areas. On top of that, a chemical filter leaves no white film on the skin.

Advantages of mineral sun protection

Immediate effect, no waiting at all: Mineral sun protection protects your skin straight after applying, so it doesn't have to soak in for 30 minutes first. That's because mineral sun protection sits on the skin and doesn't have to soak in, which is perfect for spontaneous outdoor activities.

Safe for sensitive skin: A mineral filter penetrates the uppermost skin layers not at all, or only very slightly, and forms a protective film on the skin. So it's often less irritating. Mineral ingredients are generally barely allergenic. That's why mineral sun protection is also suitable for children and people with sensitive skin or skin conditions like rosacea or eczema.

Long shelf life: Mineral filters don't tend to break down under sunlight or other environmental conditions, often stay stable longer and keep their protective effect over a longer period.

100% natural: Mineral sunscreens are made entirely from natural ingredients and contain no chemicals whatsoever. That's why, for your own health and for the environment, certified organic mineral sunscreen is generally the better fit. For babies, toddlers, pregnant and breastfeeding people, sun protection with mineral filters is explicitly recommended.

Our take:

We want to care for our skin as sustainably as possible. For us that means we don't want to rub ourselves with chemicals or other substances that demonstrably harm our body and whose full effect on our body hasn't yet been fully researched. For us it also means that, by protecting our skin, we don't want to harm the environment – especially when numerous independent studies point to it. That's why in our sunscreen we rely on the mineral filters titanium and zinc oxide, whose combination offers strong protection against UVA and UVB radiation. For the good of the environment and our body, both minerals are used in non-nano size with us. That makes our Naseweiss the perfect choice for sun protection – and that's true for children and people with very sensitive skin or skin conditions like eczema or rosacea too.

It's available with SPF50 in the Naseweiss design and in a collaboration with Die Biene Maja as well as with SPF30 in vegan.

Overview: pros and cons of chemical and mineral UV filters

Mineral filters

Advantages	Disadvantages
Immediate effect	White-cast effect
Suitable for sensitive skin, (small) children and skin conditions like rosacea or eczema	Nanoparticles of the mineral filters are controversial, because nano zinc oxide demonstrably harms corals and nano titanium oxide can trigger lung inflammation when inhaled. Further effects on the body and the environment haven't been researched enough yet. (Important: this only applies to minerals at nano size!)
Long shelf life
Only natural ingredients, no chemicals whatsoever

Chemical filters

Advantages	Disadvantages
Broad protection against UVA and UVB radiation	Some chemical UV filters are hormonally active (endocrine disrupting chemicals)
Easy to apply	Some chemical UV filters are considered carcinogenic
	Overall damage potential to the body hasn't been researched enough yet
	Harm to the environment: - Coral bleaching and death - Infertility in fish - Negative effects on green algae growth and their photosynthesis performance - Effect on the hormone balance of marine animals