Summer, sun, sun protection: as temperatures rise and days grow longer, applying sunscreen becomes part of the daily routine for many people. At the same time, chemical UV filters in particular repeatedly attract the attention of scientific studies and public debate. In this blog article you will learn how chemical sunscreens work, what potential risks they pose and how they differ from mineral sunscreens. We also present risk groups who should pay particular attention to adequate sun protection, as well as seven practical tips for a responsible and mindful approach to the sun.

Friend or foe? The positive effects and risks of sunlight

Sunlight is of great importance to the human organism and is especially known for its key role in the body’s production of vitamin D. When UVB radiation reaches the skin, the body can produce vitamin D itself, which is important, among other things, for bone metabolism, muscle function and the immune system. In addition, natural daylight influences the human internal clock, the so‑called circadian rhythm, as well as psychological well‑being. Bright daylight supports the release of various messenger substances that can have a positive effect on mood, motivation and performance.

Despite its many positive effects, the sun also carries some risks. Excessive exposure to ultraviolet (UV) radiation in particular can significantly damage the skin. In the short term, sunburn can occur — an acute inflammatory reaction of the skin associated with redness, pain and, in severe cases, blistering. In the long term, years of UV exposure can lead to premature skin ageing, which may present as wrinkles, pigment spots or a thinner skin structure, and to an increased risk of skin cancer. The often very intense sunlight during the midday hours especially increases the burden on the skin.

Healing with sunlight: The message of Autor Andreas Moritz

The alternative practitioner and multiple bestselling Autor Andreas Moritz went even further in his assessment of sunlight. His book “Heile dich selbst mit Sonnenlicht” is still regarded as one of the best‑known works in alternative health literature. Until his death in 2012, Moritz intensively explored natural healing methods as well as the influences of diet and lifestyle on health. He argued that sunlight is often unfairly demonised in public perception and reduced to its potential risks. While the dangers of UV radiation are regularly warned against, he believed that the many health benefits of moderate sun exposure are given too little attention. You can learn more about the potentially healing effects of sunlight on the human organism in our blog post Light as Elixir of Life.

According to Moritz, sunlight is one of the most important natural prerequisites for health and longevity. He held the view that humans are evolutionarily dependent on regular outdoor time and adequate sun exposure. Modern lifestyles with long periods spent indoors could, in his opinion, lead to many people receiving considerably less sunlight than would be beneficial for optimal health. Chronic lack of sunlight, Moritz argued, can promote the development of various civilisation diseases — including cardiovascular diseases, diabetes, autoimmune diseases and depression.

How do chemical sunscreens work?

Chemical sunscreens are designed to protect the skin from the harmful effects of solar radiation using specialised UV filters. Contrary to common belief, they do not work by completely blocking the sun’s rays. Instead, the UV filters they contain absorb incoming UV radiation and convert its energy into a form that is harmless to the skin — usually heat. This prevents UV rays from penetrating deeply into the skin and causing cellular damage.

The UV filters in chemical sunscreens are formulated to absorb a wide range of UV radiation — both UVA and UVB rays. Chemical sunscreen must be applied before sun exposure and takes about twenty to thirty minutes to achieve its full effect. Such products generally absorb quickly into the skin and are therefore relatively sweat‑resistant and water‑resistant. We outline the possible disadvantages of chemical sun protection in the following section.

Criticism of chemical UV filters: the main arguments

Chemical UV filters are widespread and are considered effective UV protection, used worldwide in numerous sunscreen products. At the same time, some ingredients have been the focus of scientific study and public discussion for years. The criticism generally concerns possible health effects, environmental aspects and the question of the extent to which certain UV filters can be absorbed by the body. Below we have summarised the most common criticisms and open questions regarding chemical UV filters.

1. Absorption through the skin

Although chemical UV filters are applied externally to the skin, they do not necessarily remain solely on the skin surface. Studies have shown that certain UV filters such as octocrylene, oxybenzone or avobenzone can be absorbed through the skin in small amounts after application and subsequently be detectable in the blood.¹ This provides evidence that some ingredients of chemical sunscreens can enter the body.

How these findings should be assessed in terms of health remains the subject of scientific investigation. Although systemic absorption of the mentioned UV filters has been demonstrated, this does not automatically indicate a harmful effect. Nevertheless, the long‑term safety of certain chemical UV filters continues to be debated by experts. Critics point out that the consequences of regular intake over many years have not yet been conclusively investigated, and therefore further research and stricter regulation are necessary.²

2. Potential hormone‑like effects

Another point of discussion concerns possible so‑called endocrine effects of some chemical UV filters. This refers to the ability of certain substances to influence hormonal signalling pathways. In particular, laboratory and animal studies for substances such as oxybenzone (benzophenone‑3) suggest hormone‑like effects.³ However, it has not yet been conclusively determined whether these effects are clinically relevant for humans at the concentrations actually reached. Nevertheless, the potential influence on the hormone system rightly ranks among the main criticisms of chemical sunscreen filters.

3. Environmental factors

The impact of chemical UV filters on the environment is also increasingly being questioned. Through swimming in lakes, rivers and seas, ingredients from chemical sunscreens can enter waterways and be taken up by aquatic organisms. Possible effects on coral reefs and other sensitive ecosystems are frequently discussed.⁴ Some regions — for example parts of Hawaii — have therefore restricted or banned certain UV filters such as oxybenzone and octinoxate in sunscreen products. Although the actual significance of sunscreens for coral pollution remains scientifically disputed, environmental aspects are now considered an important part of the debate surrounding chemical UV filters.

4. Possible skin irritation

Certain chemical UV filters can cause skin irritation, contact allergies or photoallergic reactions in sensitive individuals. People with sensitive skin or pre‑existing skin conditions frequently report intolerances and should be particularly cautious when using chemical sunscreens or consider alternatives.

5. The octocrylene and benzophenone issue

In recent years the UV filter octocrylene has received additional attention. Studies have shown that benzophenone, an organic chemical compound, can sometimes be detected in octocrylene‑containing sunscreens. This may be due to contamination or a breakdown product formed during storage. Investigations suggest that benzophenone concentrations can increase with longer storage times.⁵ Benzophenone is viewed critically in the scientific community because laboratory and animal studies have indicated hormone‑like properties and potential health risks. Whether the amounts detected in sunscreens are relevant for humans has not yet been conclusively determined.

Mineral sunscreens as a possible alternative

To avoid the criticisms discussed in the previous section regarding chemical UV filters, many people prefer mineral sunscreens. These differ fundamentally from chemical sunscreens both in composition and in mode of action. While chemical UV filters absorb UV radiation and convert it into heat, mineral sunscreens form a protective layer on the skin. The minerals they contain reflect, scatter and partly absorb UV radiation already at the skin surface before it can penetrate deeper.

In mineral sunscreens, so‑called “sunblockers” such as zinc oxide and titanium dioxide are typically used as UV filters. These substances mainly remain on the skin surface. Mineral sunscreens are often considered better tolerated and are therefore recommended especially for people with sensitive skin or allergies, as well as for babies and young children. In higher concentrations, zinc oxide or titanium dioxide can leave a visible white film on the skin. Modern formulations can, however, significantly reduce this effect. The texture of mineral sunscreens is also somewhat heavier than the lighter textures of many chemical products.

Who should pay particular attention to adequate sun protection?

In principle, everyone benefits from a responsible approach to the sun. However, some groups have a particularly high risk of sunburn, UV‑related skin damage or skin cancer and should therefore pay increased attention to adequate sun protection. These include people with fair skin as well as fair hair and eyes, as their skin produces less protective melanin. People with many moles or a family history of skin cancer should also avoid intense sun exposure where possible and have their skin checked regularly by a doctor.

Particular caution is also warranted for children and adolescents. Their skin is significantly more sensitive to UV radiation than that of adults. Sunburns at a young age are considered an important risk factor for the later development of skin cancer. Current studies suggest that sunburns in childhood already increase the risk of melanomas and other forms of skin cancer in later years.⁶ Other groups such as gardeners, farmers or recreational athletes, who spend long periods outdoors for work or leisure, should also take consistent measures to protect themselves from the sun. The same applies to people taking certain medications that can potentially increase the skin’s light sensitivity.

The best prophylaxis: 7 tips for sensible sun behaviour

Sunlight is extremely important for the human organism and fulfils numerous functions in the body. At the same time, excessive UV exposure can damage the skin and increase the risk of sunburn, premature skin ageing and skin cancer. Rather than avoiding the sun entirely, it is important to find a conscious and balanced approach to it. The following tips can help you take advantage of the positive effects of sunlight while protecting your skin as best as possible — including without the use of chemical sunscreens.

• Acclimatise your skin to sunlight gradually: After the sun‑poor winter months, the skin is particularly sensitive to UV radiation. Therefore, increase the time you spend in the sun step by step. Short periods outdoors allow the skin to adapt slowly to the higher UV load, which can greatly reduce the risk of sunburn.
• Rely additionally on natural sun protection: If you are wondering how to protect yourself effectively from UV radiation without using chemical sunscreens, we recommend our extensive blog post on natural sun protection. One effective measure is wearing clothing such as long‑sleeved tops, long trousers or sun hats made from tightly woven fabrics that block a large proportion of UV radiation.
• Prevent sunburn at all costs: Every sunburn represents an acute injury to the skin. Repeated sunburns increase the long‑term risk of skin cancer and accelerate skin ageing. Therefore, end your time in the sun in good time and at the latest when you notice the first signs of skin reddening. Prevention is far preferable to treating an existing sunburn.
• Avoid intense midday sun: Between roughly 11am and 3pm during the summer months, UV radiation usually reaches its highest intensity. At this time, the risk of skin damage is particularly high, so longer outdoor stays should, if possible, be scheduled for the morning and evening. This is especially important for children and people with sensitive skin.
• Spend time regularly in the shade: Direct UV exposure is significantly reduced in the shade, so for longer periods outdoors it makes sense to alternate regularly between sun and shade. Note, however, that some UV radiation still reaches the skin in shady spots. Complete sun protection cannot therefore be achieved by shade alone.
• Use sunscreen deliberately and consciously: If you use sunscreen, it should not be seen as a free pass for hours of sunbathing. Sunscreen products can complement other protective measures but cannot replace them. A sufficient sun protection factor and regular reapplication are important. Make sure to protect particularly exposed areas such as the face, ears, neck and hands.
• Support your skin from the inside as well: A balanced, plant‑based diet provides the skin with relevant nutrients it needs for its protection and regeneration functions. Fruit, vegetables, nuts and high‑quality plant oils contain antioxidants, vitamins and secondary plant compounds that can protect skin cells from damage caused by oxidative stress. In addition, adequate fluid intake helps keep the skin hydrated from within and maintains its natural barrier function.

Disclaimer

This article does not replace treatment by a qualified practitioner. The basis of this contribution is studies and current literature. It must not be used for self‑diagnosis or self‑treatment. Discuss any inspirations from this article with a practitioner you trust if necessary.

Biographical

Katharina Korbach regularly writes blog posts about medicinal plants and natural active ingredients for the Narayana Verlag. She developed an interest in language early on and began writing her own literary texts. A serious illness during her school‑leaving exams prompted an intensive engagement with health and nutrition topics that continues to this day. After repeated failures of conventional medical treatments, she decided on a more self‑efficacious, naturopathic therapeutic approach. A plant‑based diet was a key factor in her healing journey.

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