Good intentions with unintended consequences Osterwalder Euro Cosmetics Magazine

Good intentions with unintended consequences…

EURO COSMETICS Magazine • Good intentions with unintended consequences… • Uli Osterwalder • Uli Osterwalder
Principal and Owner of Sun Protection Facilitator GmbH

In this column we will discuss how good intentions can lead to unintended consequences. To set the stage, ChatGPT (OpenAI, 3.5) helped me find examples of well-intended actions with unintended consequences. Here are three of them that may also be relevant in terms of sunscreen applications:

  1. Environmental Damage: Regulations to reduce one type of pollution may inadvertently encourage the use of alternative, but equally harmful, pollutants or practices, leading to unintended environmental consequences.
  2. Unintended Behavioral Changes: Mandating certain behaviors, such as wearing seat belts, may lead individuals to take greater risks while driving, under the false assumption of increased safety, potentially resulting in more accidents.
  3. Negative Impact on Innovation: Stringent intellectual property laws can stifle innovation by creating barriers to entry for smaller competitors and hindering the sharing of ideas and technologies

Let’s explore three examples of good intentions of sunscreen manufacturers, usually heavily influenced by their marketing department, that are currently unfolding before our eyes.

1. The marketeer’s good intention NOT to use nano-sized UV filters [1]
The cosmetics industry was the first industry to introduce the term “nano” for insoluble particulate UV filters < 100 nm in size. The good intention to inform consumers was soon interpreted as a warning that the “small” nanoparticles could easily enter the body through the skin. This led to many manufacturers abandoning the use of nano-sized UV filters. Some even make unofficial and forbidden claims, such as non-nano ZnO or non-nano TiO2. If we consider all filters, organic and inorganic, soluble and insoluble, we conclude that insoluble nano UV filters are large compared to the soluble organic UV filters. The latter are in the form of individual molecules and are therefore orders of magnitude smaller than all particles (Figure 1).
Nanoparticulate (non-soluble) UV filters are declared as (nano) in the product’s list of substances and are clearly recognizable to the consumer. The much smaller, nonparticulate (soluble) UV filters are not specially labeled. According to the 500 Dalton rule, molecules with a molecular weight of more than 500 Da penetrate the skin poorly or not at all [3]. Particles with a diameter of 2 nm already exhibit extremely low permeation. The relevant permeation of substances with these flow rates is prevented by the continuous renewal of the stratum corneum [4]. Nanoparticulate (non-soluble) UV filters are labeled with (nano) in the product’s list of substances and are clearly visible to the consumer. The much smaller, non-particulate (soluble) UV filters are not specially labeled.

EURO COSMETICS Magazine • Good intentions with unintended consequences… • Uli Osterwalder • Uli Osterwalder
Figure 1. Molecular weight, size and particle diameter of soluble and insoluble (particulate) UV filters [2]. BEMT, bis-ethylhexyloxyphenol methoxyphenyl triazine; EHMC, ethylhexyl methoxycinnamate; EHT, ethylhexyl triazone; MBBT, methylene bis-benzotriazolyl tetramethylbutylphenol; PBDT, phenylene bis-diphenyltriazine; PBSA, phenylbenzimidazole sulfonic acid; TBPT, tris-biphenyl triazine.

The once well-intentioned mandate to declare “nano” has therefore had the unintended consequence that “nano” UV filters are used less today and may even disappear in the future. This would not only mean less variability in the development of sunscreens in general, but also fewer opportunities for UV filters that do not penetrate and permeate the skin. All in all: bad for sun protection.
But it’s not too late. In fact, the “nano” declaration could help promote nano UV filters once it is widely understood that “Nano” means Big [2]. I can envisage that pregnant women or mothers with young children will explicitly look for “nano” UV filters in the INCI list because they don’t want to take the risk of exposing their bodies to UV filters.

2. The marketeer’s good intention to call their sunscreens “coral friendly” [5].
This second example of potentially unintended consequences of “Coral Friendly” or “Reef-Safe” claims has also been discussed in the Sweep the Sun column [5]. After the ban of some organic UV filters in the US state of Hawaii and other islands in 2021, it became common to use this claim even in places far away from corals. The significance of the impact on corals in practice is difficult to assess (Figure 2), as the current literature shows [6,7]. However, the bans on these islands are justified on the basis of the precautionary principle, as described in a recent Lancet article entitled “Sunscreens, cancer, and protecting our planet” [8]. The UV filters in question are
mainly oxybenzone (BP-3), octinoxate (EHMC) and octocrylene (OCR), but there is also commercial information generalizing that organic UV filters are bad and the inorganic UV filters titanium dioxide and zinc oxide are good. We know it’s not that simple and can imagine the unintended consequences of the industry making such self-limitations about UV filters based on very vague, still scientifically controversial assessments. There is no method yet to rate “coral friendly” or “reef safe”.

EURO COSMETICS Magazine • Good intentions with unintended consequences… • Uli Osterwalder • Uli Osterwalder
Figure 2. Simplified overview of potential input and exposure pathways of UV filters to coral reefs [7]

The unintended consequence on islands where UV filters are banned can mean more sunburns and higher rates of skin cancer in the longer term, because people can’t find the sunscreen they like to apply. This problem needs to be solved locally; I remember a boat trip to the Great Barrier Reef more than 25 years ago where no sunscreen was allowed while snorkeling. A wetsuit or a good T-shirt and a hat probably protect better than sunscreen anyway.
On the other hand, the unintended consequences of “coral friendly” and “reef safe” claims on the mainland and on coasts far from coral reefs are similar to other “free from” claims. In most cases, such claims are indeed based solely on the fact that the UV filters BP-3, EHMC and OCR are not part of the formulation. Does this automatically make a sunscreen “reef safe”? Certainly not, things are much more complex. It will take some more research and risk assessment calculations before we can properly substantiate such claims. In the meantime, hasty claims about coral friendliness undermine sunscreens by sowing doubt about their safety. This can lead to people using less sunscreen and risking not only sunburn but also skin cancer.
In summary, a local ban on sunscreens based on the precautionary principle may be in order. However, the claims “coral friendly” or “reef safe” cannot (yet) be scientifically substantiated and should therefore not be used globally. The unintended consequence of such industry behavior is to undermine confidence in the use of sunscreens.

3. The marketeer’s good intention to ban UV filters with impurities traces [9]
The story about “Phthalates in children’s urine and their possible cause” was discussed in the last Sweep-the-Sun column [9]. I posed the question, “Will we lose another UV filter”. The good intention is that eliminating DHHB or even banning it would reduce phthalate concentrations in children’s urine. However, it is questionable whether and to what extent this would actually work, whereas there would also be unintended consequences. A second, more comprehensive assessment statement by the German Federal Institute for Risk Assessment (BfR) has now come to the following conclusion:

…the concentrations of the substance mono-nhexyl phthalate (MnHexP) detected in urine samples do not give rise to increased concern. The detected concentrations are within a range that has also been determined for other phthalates in the context of serial tests [10].

As you can see in the selection of UV filters in Figure 3, DHHB plays an important role in UVA protection. Sunscreens rarely consist of only one UV filter, but several UV filters are required to achieve high sun protection factors and balanced UVB/UVA protection.
As we now know, UVA radiation can also contribute to the development of skin cancer.

EURO COSMETICS Magazine • Good intentions with unintended consequences… • Uli Osterwalder • Uli Osterwalder
Figure 3 Selection of UV Filters covering both UVB and UVA [11] EHT, ethylhexyl triazone; TBPT, tris-biphenyl triazine; EHMC, ethylhexyl methoxycinnamate; OCR Octocrylene; DHHB, Diethylamino Hydroxybenzoyl Hexyl Benzoate; BEMT, bis-ethylhexyloxyphenol methoxyphenyl triazine; BDBP, Bis-(Diethylaminohydroxybenzoyl Benzoyl) Piperazine; MBBT, ethylene bis-benzotriazolyl tetramethylbutylphenol;

In conclusion, it is advisable that manufacturers of UV filters and sunscreens keep a cool head when ingredients of their formulations are under attack, and stick to the science. The precautionary principle works both ways: Protecting people and protecting the environment [12]. Ultimately, we arrive at Diffey’s risk management approach to UV radiation [13], with the addition of risk assessment and risk management of the sunscreen itself [9].

4. What if the court of public opinion is still indicting the sunscreen industry?
It’s good to stick to the science and keep a cool head, but you shouldn’t lose sight of the public-relations aspect either. How should you deal with accusations and bad news? Ideally, you can simply ignore them and wait for them to die down. However, if the noise gets bigger or mistakes have been exposed, it’s wise to follow the advice of James Carville, a prominent political strategist who worked on Bill Clinton’s presidential campaign (recreated by ChatGPT):

  1. tell the truth: Be honest and sincere about the situation.
  2. say it all: disclose all relevant information instead of trying to withhold details.
  3. tell it early: address the issue as soon as possible rather than letting it fester or waiting until it becomes a bigger problem.
  4. tell it yourself: Take ownership of the narrative and communicate directly with the public rather than letting others take control of the story.

While this advice is often associated with Carville, it’s worth noting that similar principles have been advocated by various crisis management experts and public relations professionals.

5. Conclusion
Having good intentions and acting on them is fine, but potential unintended consequences should be explored with such actions. Also, don’t lose sight of the purpose of UV/sun protection and get serious about skin cancer prevention [14].
Stay tuned.


  1. Osterwalder U, NANO means BIG!, Sweep-the-Sun, Column, EURO COSMETICS Magazine, 2023-04-05,, accessed 2024-05-05
  2. Surber C, Plautz J, Dähnhardt-Pfeiffer S, Osterwalder U. Size Matters! Issues and Challenges with Nanoparticulate UV Filters. Curr Probl Dermatol. 2021;55:203-222. doi: 10.1159/000517632. Epub 2021 Oct 25. PMID: 34698039.
  3. Bos JD, Meinardi MM. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Exp Dermatol. 2000;9(3):165–9. doi: 10.1034/j.1600- 0625.2000.009003165.x
  4. Watkinson AC, Bunge AL, Hadgraft J, Lane ME. Nanoparticles do not penetrate human skin: a theoretical perspective. Pharm Res. 2013;30(8):1943–6. doi: 10.1007/s11095-013-1073-9
  5. Osterwalder U, Reef-safe sunscreen: environmental concern or marketing hype? Sweep-the-Sun, Column, EURO COSMETICS magazine, 2023-09-10, accessed 2024-05-05
  6. Mitchelmore CL, Burns EE, Conway A, Heyes A, Davies IA. A Critical Review of Organic Ultraviolet Filter Exposure, Hazard, and Risk to Corals. Environ Toxicol Chem. 2021 Apr;40(4):967-988. doi: 10.1002/etc.4948. Epub 2021 Feb 2. PMID: 33528837; PMCID: PMC8048829
  7. Renegar A, Dudley DK. Interpreting Risk from Sunscreens in the Marine Environment. Curr Probl Dermatol. 2021;55:259-265. doi: 10.1159/000517636. Epub 2021 Oct 25. PMID: 34698047.
  8. Galamgam J, Linou N, Linos E. Sunscreens, cancer, and protecting our planet. Lancet Planet Health. 2018 Nov;2(11):e465-e466. doi: 10.1016/S2542-5196(18)30224-9. PMID: 30396433.
  9. Osterwalder U, Plasticizer in children’s urine – are we about to lose another UV-filter? Sweep-the-Sun, Column, EURO COSMETICS magazine, 2024-03-21,, accessed 2024-05-04
  10. Bundesinstitut für Risikobewertung, 2024. MnHexP in Urinproben: Bewertung des gesundheitlichen Risikos: Stellungnahme Nr. 017/2024 des BfR vom 21.März 2024, BfR-Stellungnahmen. Bundesinst. für Risikobewertung.
  11. Hueglin D, BASF Research Press Conference, Ludwigshafen, March 29, 2012
  12. Diffey B. Sunscreen and the Precautionary Principle. Curr Probl Dermatol. 2021;55:394-399. doi: 10.1159/000517647. Epub 2021 Oct 25. PMID: 34698028.
  13. Diffey B, Sun Protection: A Risk Management Approach, IOP Publishing Ltd, Institute of Physics Publishing, Bristol, UK (2017)
  14. Osterwalder U, Imagine if … we were serious about preventing skin cancer!, Sweep-the-Sun, Column, EURO COSMETICS magazine, 2023-12-07,, accessed 2024-05-05
EURO COSMETICS Magazine • Uli Osterwalder • Uli Osterwalder • Uli Osterwalder
Uli Osterwalder

Uli Osterwalder studied Chemical Engineering at ETH Zurich, Switzerland and at the University of Houston in Houston, Texas. He joined Ciba-Geigy in Basel in 1979 where he first developed a Phosgene Generator in central process development. Later he developed his leadership skills in Project Management and Process Analytics. At Ciba Specialty Chemicals Uli Osterwalder helped establish new business development in Fabric Care and Personal Care. After the acquisition by BASF SE he became Senior Marketing Manager and Scientific Adviser in Sun Care in Ludwigshafen and Duesseldorf.
2016 he came back to Basel, working for DSM as senior Senior Scientific Adviser suncare for two years. 2018 he started his own company, Sun Protection Facilitator GmbH and is committed to contribute to further improvements in sun protection. Uli Osterwalder works for ISO on the development of new UV protection assessment methods and is now chairing the technical committee ISO TC/217 (Cosmetics). He is author and co-author of numerous scientific articles and book chapters on sun protection.

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