SNV Story No. 7: DSM

Sun protection is vital. The skin never forgets!

Summer, sun and the beach … the time has finally come. But the sun can also have its darker side, says Dr Jürgen Vollhardt from DSM. It is a mood enhancer, essential to vitamin D production, and even helps to lower blood pressure. At the same time, however, we’ve probably all come home from a holiday with sunburn as a souvenir at one time or other, and know the pain and after-effects that come with it. While our holiday memories slowly fade once we get back into everyday life, our skin will remember each ray of sunshine for years to come. Skin cancer numbers continue to rise, with Switzerland having the dubious distinction of being No. 1 in Europe.

The dark side of the sun
Around 5% of sunlight arrives in the form of high-energy ultraviolet (UV) radiation. But what exactly is the difference between UV-A and UV-B rays? Put simply, UV-B rays only reach the uppermost layer of the skin and produce the familiar reddening, i.e. sunburn, while UV-A rays penetrate into the deeper layers and are more responsible for skin ageing. Unfortunately, both types also contribute to the development of skin cancer, with UV-B having a much greater impact. Even glass panes cannot completely block UV-A rays. «The NEW ENGLAND JOURNAL of Medicine» published an impressive image of this in 2012. After 28 years on the job, the left side of a truck driver’s face has aged much more significantly, even showing various health-damaging changes.

Image: Energy distribution of solar radiation at sea level
While UV accounts for only a small part of the energy, the individual energy content of each photon means it is able to cause molecular change. Unfortunately, the positive effects of sunlight (mood enhancement, tanning, vitamin D, lower blood pressure) go hand in hand with the negative ones, i.e. they happen simultaneously. The recommendation here is to limit the dose and avoid full sunburn, even with sunscreen. A vitamin-rich diet can help to prepare the skin for oxidative stress. This should not be overdone either, however, as the skin’s antioxidant reservoir will be used up at some point. (Source: DSM)

UV protection in a tube
Taking various different approaches to sun protection is essential, and seeking shade, protective clothing and high-quality sunscreen all help. According to public sources on the Internet, the first sunscreen was launched in 1933. This development was motivated by the more revealing swimwear and the popularity of sports involving increased exposure to the sun. SNV member and materials and life science company DSM is committed to creating a better life for all, and focuses among other things on developing UV filters for sunscreens. You will surely have been faced with the challenge of choosing between them at some point: creams, sprays, lotions, SPF options, water-resistance, 24-hour protection, chemical filters, physical (including mineral) filters. What makes the vital difference is not price, but ingredients and efficacy, indicated as sun protection factor (SPF). If you use an SPF of 30, for example, you are 30 times better protected than without sunscreen and the appearance of redness will be correspondingly delayed. Dr Vollhardt explains, however, that the protection factor indicated on the packaging can only be achieved if the recommended amount is used. It is also essential to apply the product before going into the sun, and to avoid any gaps in application. Unfortunately, this is often not the case and the protective effect is reduced accordingly. Based on an impressive example of his own, with a standard application concentration of 0.4 mg/cm2, which corresponds to one fifth of the recommended amount, it must be assumed in practice that a lotion with SPF 30 on the beach also provides only one fifth of the UV protection, i.e. SPF 6. While this will protect you from dangerous sunburn on most beaches and allow you to continue your holiday, it is not enough for cancer prevention. When asked whether this should not be made clear to avoid lulling sun worshippers into a false sense of security, Dr Vollhardt says: «In principle, consumers can’t be told how much sunscreen to use, but only recommended. An explicit warning might not be a bad thing, however. What is self-evident to me as a scientist, namely ‘smaller quantity = less protection’, may not be so clear to everyone. The SPF claim is always related to the amount applied. Our industry has been competing to provide higher and higher SPF values in recent years, and today even SPF 100 is available in the US. It’s true that nowhere on earth does the sunlight last long enough for such a factor to be needed at all if the sunscreen is applied correctly. On a positive note, however, the high SPF compensates for the insufficient amount of product used by some consumers – even just a fifth of the recommended amount would still provide an SPF of 20. I think a practical SPF of 10 to 15 on the beach would have a clearly positive impact on cancer statistics, whereas SPF 5 is nowhere near enough!»

Gold standard UV filters
The testing procedure for sun protection factors has been standardized worldwide. The SPF method described in the SN EN ISO 24444:2020 standard and the comparable method in the USA as defined by the Food and Drug Administration (FDA) for SPF measurement require labour-intensive, lengthy and complex human testing. This involves exposing test subjects to erythemal doses of UV radiation on a small area of skin, and an alternative method has been sought for some time. In addition, the complexity of the procedure and various inaccuracies of this biological testing (human subjects, application of the sunscreen by humans and read-out by humans) lead to relatively large random variability, especially between different laboratories performing the tests. In the last two to three decades, alternative methods such as in vitro transmission tests, in silico calculations and non-invasive in vivo tests (with negligible UV doses used on humans) have emerged. The current developments are a cause for concern, and draw attention to these methods as promising alternatives. Comparison of alternative SPF data with the gold standard calls for a solid data set and thus extensive testing, which the International Organization for Standardization (ISO) cannot afford. This is why the basic idea for the ALT-SPF project was formed in 2018. Uli Osterwalder and Dr Jürgen Vollhardt, both at DSM and SNV members at the time, launched a round robin study together with other well-known companies such as Beiersdorf, L’Oréal, Johnson & Johnson and later also Mibelle. The aim of an alternative measurement method is to provide more accurate figures and make them easily reproducible and more affordable for being carried out by all laboratories worldwide. The initiative aims to pool resources to realize long-awaited comparability with the in vivo SPF method as defined by the «gold standard ISO 24444». Dr Vollhardt reminds us that the SPF test method has a direct effect on relevant damage in human skin. Damage that needs to be prevented. This is what lends it the distinction of the gold standard.

ALT-SPF and ISO go hand in hand
ISO develops international standards on a voluntary basis with experts from industry, as well as other stakeholders such as authorities and consumer organizations. The costs are shared by all concerned, and extensive validation involves significant additional work. This is where the ALT-SPF consortium comes in, aiming to ensure that characterization is carried out according to scientific standards and that every relevant alternative method is given a chance, emphasizes Dr Vollhardt. The resulting data are prepared in such a way that they can be validated by interested authorities or standardization bodies. The alternative measurements should neither overestimate nor underestimate SPF values. The most important aspect for sunscreen users is that, regardless of the measurement process applied, a current SPF 30 product remains a 30 even in future non-human testing procedures.

Bild: The interplay between ISO and ALT-SPF (Source:

PARSOL – first-class UV filters
The PARSOL UV filters from DSM meet high quality standards, and are successful worldwide. PARSOL1789 is THE global UV-A filter, the only one registered and approved worldwide, i.e. including in the USA. In other words, sunscreen manufacturers in the US have no alternative. It is no wonder, then, that DSM filters are used in about 80% of all sunscreen for the face and almost 70% for the body. Various standards from the ISO/TC 217 «Cosmetics» committee are applied in the development of UV filters. «These standards help us to measure product performance in all countries according to the same principles. You can therefore buy local products anywhere in the world nowadays and trust that the level of protection has been measured according to international (ISO) standards. As a member of the Swiss Association for Standardization (SNV), we benefit above all from being able to collaborate and participate in these measurement procedures, and this is also important when it comes to new UV filter developments. We recently discovered that some UV filter systems in our range behave very intelligently on the skin, achieving a much better performance than expected. These research findings also flow directly into the development of new generations of UV filters. Here it is important that these effects can also be mapped in alternative in vitro determination methods,» explains Dr Vollhardt.

A careful choice of sunscreen
A good sunscreen does not have to be expensive. Dr Jürgen recommends: «Make sure you like the application of the sunscreen product, as there are significant sensory differences and various product forms. Feel free to experiment with several products, and find the best feeling for your skin. This is especially true for men. They have particularly high expectations of ‘well-tolerated’ products, and tend to avoid sun protection altogether if it feels uncomfortable on their skin. At least SPF 30, and don’t skimp on the quantity. Sunscreen is important for everyone. Another tip is to question generalized claims that sunscreen is harmful. Nowadays, any suspicion of potentially dangerous ingredients spreads like wildfire – in conventional media, and especially in social media. As we all know, bad news sells better than good. Unfortunately, most suspicions are not based on any actual risk assessment. Such half-knowledge unnerves consumers, and failing to use sun protection could be disastrous for our health. All UV filters available on the market have been tested for their safety in use on humans, as well as being approved by the authorities in accordance with the applicable regulations. Every new substance is put through its paces, and old ones are retested if necessary. Dangerous substances have no chance of being approved – all approved UV filters are safe for humans. Trying to distinguish between the good and the bad makes no sense from a scientific perspective. As far as environmental acceptability is concerned, we have now developed a rating system based on studies. This can be used by manufacturers to estimate the influence of the highly complex parameters before any time-consuming laboratory work needs to be done, and compare them with an industry average. If this system gains acceptance, it will become a relevant driver in the development of even better environmentally acceptable sunscreens. Ideally, we also aim to develop a standard and a packaging label for this rating system. This will provide consumers with a scientific basis for decision-making, and help ease the burden on the environment. Put simply, then, find a sunscreen with at least SPF 30 that you enjoy using. In the long run, there’s no other way.»

Suntans and coral bleaching
For some time now, environmental organizations have been warning that the chemicals contained in sunscreens are contributing to the death of coral reefs. The maritime states affected have responded, with the use of oxybenzone and octinoxate having been prohibited in the Hawaii Ban in the state of Hawaii since 1 January 2021, for example. While Dr Vollhardt acknowledges consumer motivation to reduce the negative impact of their behaviour on the environment, he definitely does not support the counter-trend of using no sunscreen at all: «I’m shocked and concerned by recommendations on online forums or social media to avoid using sunscreen. This is especially risky in places like Hawaii and other beach locations with high sun exposure. Skin cancer rates were already on the rise before the ban, and my fear is that the new law could make this situation worse.» It might sound paradoxical for a company in the chemical industry, but sustainability is a strategic topic at DSM. They ensure that any negative impact, as well as safety risks to human, animal and environmental health along the entire value chain, are controlled and minimized. And is sunscreen really the only factor responsible for coral death? «Well, scientific data suggest that rising water temperatures and pollution from sewage are the main stress factors for corals. UNESCO published its first global scientific assessment of the impacts of climate change on World Heritage coral reefs in 2017. This study linked severe and repeated heat stress as a result of rising sea temperatures to coral bleaching at key sites. In addition to this, we know that coral bleaching also occurs on remote reef sites where sunscreen does not reach the water. So there is a chance that the ban in Hawaii will not save the coral reefs,» explains Dr Vollhardt.

Shade loving or sun seeking
How does someone who deals with sunscreens and UV filters and skin cancer statistics on a daily basis in their professional life actually behave? How do they feel about the sun? «Just like lots of other people, I love the summer, this time of intense brightness, and I also enjoy spending time outdoors mountain biking or climbing. And then I use plenty of sunscreen. A brand that absorbs quickly and leaves a relatively dry and matte film on the skin. If I’m outside around midday, I apply two layers in quick succession. Two hours after the sun reaches its zenith (at around 1.30 p.m. in Switzerland), UV-B radiation is only 50% as strong. This does not apply in the mountains, however, and this is especially relevant in Switzerland. Yes, and I take vitamin D tablets in the darker season from October to March. I do love fish, which can also contain vitamin D, but not every day,» he grins.

Enjoy the beneficial aspects of the sun and protect yourself every day – even when the sky is overcast, and in winter. The sun’s rays never take a break.

The Swiss Association for Standardization (SNV) wishes you a pleasant and sunny summer!

Seealpsee / Image: Jan Benisch

Switzerland – the exception to the rule
Switzerland has neither beaches nor 365 days of cloudless sunshine. So why do we have the highest skin cancer statistics in Europe? Is our skin just more sensitive, or do we have our skin checked more often? «It can be assumed that general behaviour plays a significant role here. Holidays to equatorial destinations are very popular with the Swiss, as are holidays in the mountains of Switzerland itself, of course. Both are areas with extreme radiation exposure, especially UV-B. Most Swiss people are aware that mountain activities involve accident risks, and are prepared to protect themselves and behave accordingly. In all other respects, however, a stay in the mountains is thought of as being extremely healthy, and visitors are sure to return home in high spirits. But precisely because of the extreme radiation exposure, effective sun protection is particularly important here, especially in winter. Even mild sunburn after a mountain or ski tour with too little sunscreen poses a significant risk of skin cancer. Better to apply a second layer of sunscreen as soon as the first has been absorbed. Things go quickly in the mountains. Wear a hat and a T-shirt that covers the shoulders to avoid regretting the trip much later down the line,» advises Dr Vollhardt.

Founded in 1902, today Royal DSM is a global company active in nutrition, health and sustainable living. DSM provides innovative solutions for human nutrition, animal nutrition, personal care and flavours, medical devices, environmentally friendly products and applications, as well as new mobility and connectivity. DSM is a member of the SNV committee INB/NK 1217 «Cosmetics and Beauty Salon Services».

Dr Jürgen Vollhardt
Dr Jürgen Vollhardt, Global Head of Science & Promotion Sun Care, holds a doctorate in chemistry from the Technical University of Darmstadt in Germany. After receiving his doctorate, he went on to help Dragoco/Symrise, a flavours and fragrances company, to build up its cosmetics research activities. From 1999 to 2003, he was responsible for business development in active ingredients in skincare, based in the USA. In 2003, he moved to Roche Vitamins in Switzerland, which shortly afterwards became part of DSM Nutritional Products, where he became increasingly involved in sun protection. His areas of interest include sensory evaluation of cosmetic formulations, and the related consumer acceptance. He has also worked on the distribution of UV filters on the skin, and how this affects their efficacy. For more than a decade now, he has been a member of WG 7 «Sun Protection Methods» for the Swiss Association for Standardization (SNV).

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