Why I only use mineral UV filters

When we ask: What suncare do you wear? we’re not looking for the perfect answer - but for awareness.
With the relaunch of Karmameju SUN, founder Mette Skjærbæk shares in this article why choosing a sunscreen is an important decision – for both our skin and our health.

You can also read about the differences between sun filters, and why Mette, based on the precautionary principle, chooses exclusively mineral sun filters – for herself, for her daughters and for everyone who uses Karmameju Skincare.

My reasons for choosing exclusively mineral sun filters are many, but above all they come down to the precautionary principle.

Regulations concerning chemical sun filters are continuously updated in light of new scientific assessments. Nanotechnology in skincare is still an evolving field of research - therefore, we have chosen to avoid it based on the precautionary principle.

For me, mineral sun filters are the safest choice, and they have been ever since my twenties, when I first became aware of how skincare ingredients can affect our vital body systems and overall health.

Mineral sun filters are an essential part of Karmameju’s holistic values, the promise I have made to those who use Karmameju - and what I wish to pass on to my daughters.

Since the 1990s, I have used only mineral sunscreen on my family and myself, and it is such a joy that Karmameju’s sunscreen does not leave you sticky and white, as mineral sunscreens used to.

There are so many advantages to mineral sun filters:
– They work immediately after application
– They occur naturally in the earth
– They provide broad-spectrum protection instantly
– They do not clog the skin
– They do not leave permanent yellow stains on clothing
– They do not sting the eyes
– They are recommended for sun allergy and rosacea
– They are recommended for children


Developing Karmameju SUN has not been easy. With the first version of our mineral sun filter, I felt we reached 90% of the way in making it invisible on the skin and easy to apply. With the new version (2025), I believe we have fully achieved our goal.

The “easy” solution would have been to use chemical sun filters or mineral filters in nano form and to add silicone to the formula to make it easier to spread. None of these three options align with my holistic values.

We do not use mineral nano sun filters, whose particles are made microscopically small through nanotechnology, based on the precautionary principle.

Chemical sun filters only become effective once they have penetrated beneath the skin’s surface; this happens through a chemical process in which the UV rays are converted into heat. Over time, UV filters have been the subject of debate and ongoing regulation in the EU, as new research assesses their safety*.

For example, in 2025 a team of researchers from Rigshospitalet (Copenhagen University Hospital) found degradation products of the substance DnHexP in urine samples from the majority of the 1,591 people tested, particularly in children*. DnHexP is a phthalate that is classified as an endocrine disruptor and is banned in cosmetics in the EU. Nevertheless, the substance is found because one of the most widely used chemical sun filters, DHHB, may be contaminated with it during production. In Germany, similar findings have been made in urine samples from children and adolescents, and in a study from 2020–2023, a government research institute tested 40 different sunscreens containing the chemical sun filter DHHB and found traces of DnHexP in 50% of the tested products*.

Another example from here in Denmark is a 2024 study from Rigshospitalet, where a chemical UV filter (now classified as an endocrine disruptor) was found in the follicular fluid of all 111 women tested who were undergoing fertility treatment*.

Findings like these have helped strengthen my decision to work according to the precautionary principle. It is a development I follow closely, and one that confirms my decision to use only mineral sun filters. It is
the promise I have made to those who use Karmameju - and what I wish to pass on to my daughters.

Fortunately, we have succeeded in creating a sun range with the mineral sun filter zinc oxide, which in our updated formula (2025) continues to provide optimal broad-spectrum protection, but is now even easier to use and, most importantly (this was our greatest challenge), our new mineral sun filter is invisible on the skin.

It brings me great joy that we have succeeded in creating such a lovely, nurturing sunscreen based solely on mineral sun filters, and as I see it, there is no longer any reason to use anything other than mineral sun filters.

It is a cause close to my heart to make people aware that the choice of sunscreen is an important decision - for both our skin and our health. The skin is our largest organ – it is an organ that distributes; think, for example, of how medication applied to one area of the body via a cream, gel or patch is then distributed by the skin throughout the entire body. The skin is so important for our overall health, with its delicate pH value and its fine microbiome. The health of the skin, including SPF, has been documented as essential for a long life/ longevity - you can read more about that in this article I have written about how essential the health of the skin is for us as human beings.

Mineral sun filters, such as our non-nano zinc oxide, protect the skin by absorbing UV radiation while also reflecting and scattering part of the radiation away from the skin’s surface – which means protection is immediate.

Chemical sun filters must penetrate the skin, where they absorb UV rays and convert them into heat through a chemical process. Personally, I don’t like the idea that chemical sun filters only start working after 20 minutes**, once they have penetrated the skin.

Together with our highly valued manufacturer in Southern Italy, which has organic fields as far as the eye can see, we have succeeded in “cracking the code” to making mineral sun filters lovely to use, which is the starting point for wanting to use your sun protection - several times a day.

The balance between the easy application and the moisture-binding ingredients, including organic aloe vera, organic shea butter, softening plant oils and active plant extracts, has resulted in us succeeding in creating a sun range, all the way up to SPF 50+, that does not leave you white and leaves the skin beautiful and well cared for. Because we have decided that it is not just sun protection we create in Karmameju SUN; it is nourishing, caring, antioxidant-rich skincare, so that when you apply it, you give your skin the best conditions to thrive in the harsh rays of the sun.

- Mineral sun filters, also called physical sun filters, which Karmameju uses

- Nanoparticle sun filters: sun filters in nano form

- Chemical sun filters

Mineral sun filters
Mineral/physical sun filters, zinc oxide (which Karmameju uses) and titanium dioxide, consist of minerals of natural origin from the earth. Mineral sun filters, zinc oxide (which Karmameju uses) and titanium dioxide, protect the skin by absorbing UV radiation while also reflecting and scattering part of the radiation away from the skin’s outermost layer – which means the protection is immediate. We prefer physical filters, as several years of research suggest that they are highly photostable and less likely to irritate the skin***. Most importantly, they mainly settle in the skin’s outermost layer (epidermis). Sunscreens with physical sun filters are known for being difficult to spread and for leaving the skin with a whitish cast, but that is not the case with Karmameju SUN.

Mineral/ physical sun filters: Zinc Oxide. Titanium Dioxide.****

Nanoparticle sun filters
Many ingredients can be made in a microscopic nano size. For example, physical sun filters have been created in nano form to make the filters less visible on the skin and thus less white. Most studies show that nanoparticles in sun filters do not penetrate intact skin, i.e. a healthy skin barrier*****, which is why nano is generally advised against on a compromised skin barrier (e.g. with sunburn or eczema). Because nanotechnology is still an evolving field of research, we have chosen to avoid it based on the precautionary principle. Ingredients in nano form are always listed with “nano” in parentheses after the name, e.g. Titanium Dioxide (nano), so that consumers can see that nano ingredients have been used in the product. Karmameju does not use nano sun filters.

Nanoparticle sun filters: All sun filters listed with (nano) in parentheses after the ingredient name.****

Chemical sun filters
Chemical sun filters are synthetic. When UV rays hit the skin, the sun filters absorb the UV radiation and convert the rays into heat within the skin through a chemical process. Some studies have shown that certain chemical sun filters penetrate the skin barrier (dermis), can be measured in the blood and may cause skin irritation and trigger sun allergy***.
Chemical sun filters cannot be seen when applied to the skin and are therefore used by many skincare brands. None of the chemical filters are approved by the “green” certification ECOCERT/COSMOS.

Chemical sun filters: Diethylamino Hydroxybenzoyl Hexyl Benzoate. Ethylhexyl Triazone. Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine. Diethylhexyl Butamido Triazone. Ethylhexyl Salicylate. Octocrylene. Oxybenzone. Avobenzone. Octinoxate. Tinosorb. Ethylhexyl Methoxycinnamate. Homosalate. 4-Methylbenzylidene Camphor (4-MBC)(1 May 2026: All existing products containing the filter must be removed from shop shelves.) etc.****

Most of us love the sun, myself included - and there are also many benefits to letting the warm rays of that beautiful ball of fire kiss our skin. But using a safe sunscreen is essential for our health and safety.

Consumer safety is the guiding star in our product development. Thank you for your trust in Karmameju - it means the world.

With love

Mette Skjærbæk
Founder of Karmameju

*The Danish Health Authority on the chemical sun filter 4-MBC, which is no longer permitted for use in
sunscreens within the EU (link)

*Study from Rigshospitalet (Copenhagen University Hospital) that found degradation products of the substance DnHexP in urine samples from the majority of the 1,591 people tested (link)

*Study by the German authorities, which found the endocrine-disrupting phthalate DnHxP in 50% of the 40 sunscreens tested containing the chemical sun filter DHHB on the German market (link)

*Study from Rigshospitalet (Copenhagen University Hospital) that found residues of an endocrine-disrupting chemical sun filter in follicular fluid samples from couples undergoing fertility treatment (link) (link to study)

**The Danish Health Authority (2025) on applying sunscreen 20 min. before sun exposure (link)

*** On the link between sun allergy and sun filters (link) (link)

**** The above lists were compiled in March 2026. Legislation on which sun filters are considered safe for consumers is continuously changing – so always seek up-to-date information about your sunscreen at the given time.