Skin Cancer and Sunscreen: Are We Confusing Protection for Chemical Warfare?
Not a Scientist, Not a Doctor — Just a Founder Who Refused to Look Away
I'll be the first to admit it: I'm not a scientist or a chemist. I have one of those on our team already. I'm not a doctor either - we have one of those at EthoSun too. What I am is a CEO and founder who decided, for better or worse, to go as far down the rabbit hole of transparency, compliance, and regulation as I possibly could.
Someone throw me a carrot down here, because of how long I've spent doing it: late nights reading studies and articles, comparing data, digging through regulation after regulation. But somewhere in that process, I realized something. I can, and I will, stand in the fire and fight for transparency and skin health now more than ever.
This isn't just about the brand I built, or the award-winning products I'm proud to call EthoSun. It's about the fight for toxin-free SPF and clean products. It's the fight to debunk the marketing spin and lies circulating on social media. It's the fight to change what we put on our skin, and to make real sunscreen education and skincare education as common as the myths themselves.
So I did the deep dive. I went down the rabbit hole, and I stand behind what I found: the truth about SPF carcinogenics, toxic chemicals, and the fight to uncover and expose the dirty truth of the beauty industry, because real sun protection shouldn't come with hidden costs.
There is a major study circulating about higher incidence of skin cancer in those who use sunscreen vs those who do not use sunscreen: "470,000+ people in the study and it was found that sunscreen users had up to 292% higher risk of skin cancer." Understandably, these numbers are shocking enough to scare people away from grabbing for their next sunscreen application. As an educated consumer, we want the sunscreen facts, not just the headlines!
Digging deeper into the research and data, there is no true cause and effect. No perfect a+ b = c for the answers or reason to blame for a horrific disease. This is where science states there is association but not causation. It's a distinction that fuels plenty of sunscreen misconceptions, outright sunscreen myths, and even a few mineral sunscreen myths that swing the pendulum too far in the other direction. Science is also highly aware that consumers are subject to oversight by regulatory associations, with the expectation that these associations have thoroughly studied the safety of these substances. In reviewing these chemical ingredients, we see these issues:
Oxybenzone and its concerns: Oxybenzone is a chemical UV filter that absorbs both UVA and UVB rays, helping prevent sunburn and some UV damage. Oxybenzone is probably the most controversial of all sunscreen ingredients. Studies have shown that it is readily absorbed through the skin and can be detected in blood, urine, breast milk, and even amniotic fluid after repeated use. Laboratory and animal studies suggest oxybenzone may interact with estrogen, androgen, and thyroid hormone receptors, leading to concerns about endocrine disruption. Human studies have been less definitive, but enough questions remain that many consumers choose to avoid it.
It has also been linked to coral reef damage, contributing to bleaching and developmental abnormalities in marine organisms, which led to restrictions in places such as Hawaii and Palau.
Homosalate: Homosalate primarily protects against UVB rays, the rays responsible for sunburn. Homosalate is absorbed through the skin and may accumulate in the body with repeated application, which matters if you're using it as sunscreen every day. Laboratory studies suggest it may have weak hormone-like activity, particularly affecting estrogen and androgen pathways, although the relevance to human health is still being investigated. The European Union reviewed the available evidence and lowered the maximum allowable concentration from 10% to 7.34% because they concluded the previous concentration could not be confidently considered safe with repeated exposure.
Octinoxate: Octinoxate is one of the most common UVB filters used in conventional sunscreens. Like several other chemical filters, octinoxate is absorbed into the bloodstream after application. Laboratory research has suggested potential effects on thyroid hormones and reproductive hormone signaling, although human evidence remains limited. It is also considered harmful to marine ecosystems and has been shown to contribute to coral bleaching and developmental effects in aquatic organisms. Hawaii banned sunscreens containing octinoxate because of these environmental concerns.
Octocrylene: Octocrylene absorbs UVB and short UVA rays. One reason manufacturers like it is that it helps stabilize avobenzone, preventing avobenzone from rapidly degrading in sunlight. Octocrylene has become increasingly scrutinized because it can slowly break down into benzophenone, a compound classified by the International Agency for Research on Cancer (IARC) as possibly carcinogenic to humans based on limited evidence. This degradation can occur during storage, particularly as products age. Octocrylene is also associated with allergic skin reactions in some people, especially children and individuals with eczema. Like oxybenzone and octinoxate, it has raised concerns regarding marine toxicity. Concerns include: stability issues, benzophenone formation, skin allergy potential, and environmental concerns that make it one of the more debated ingredients.
Avobenzone: Avobenzone is one of the few FDA-approved chemical filters that provides strong UV protection against UVA rays, which are responsible for premature skin aging and contribute to skin cancer risk. Avobenzone itself isn't considered a major endocrine concern compared with oxybenzone, but it has another challenge: it is highly unstable in sunlight. Without stabilizing ingredients (often octocrylene), avobenzone can lose much of its protective ability after UV exposure, which is exactly why sunscreen reapplication matters regardless of which filter you choose. Manufacturers frequently combine it with additional chemicals to improve stability, meaning one ingredient often leads to several others being added to the formula. As avobenzone degrades, it may also generate reactive breakdown products, although the health significance of these compounds is still being studied. Overall, it is effective UVA protection, but chemically unstable on its own and typically requires other ingredients to keep it working.
Now the bigger question is: are these enough to warrant the headlines going around? Can either of these, or a combination of these, cause cancer? Because causation is not the same as correlation, all these companies can hide behind this statement. Choosing the best sunscreen isn't just about the SPF number on the label. As consumers, we have to wonder about the grey areas and ongoing research needed for these chemicals. Each ingredient has its own caveat of how impactful it may be on humans and coral reef health. If we put more than one ingredient together, what does this mean? We now have more than one ingredient in a mix, with each ingredient adding on top of the other. The cumulative impact of each ingredient alone would be enough to be concerning. Two, three, maybe four ingredients altogether increase the chance of negative impacts on the body. As much as the research does not support that sunscreen is a true cause for skin cancers, as a savvy consumer or business owner, it is a critical consideration to put the health of your island reef, and the healthy skin of your customers, as a priority without compromise or question.
By comparison, non-nano zinc oxide is a single mineral UV filter that naturally provides broad spectrum sunscreen protection against both UVA and UVB rays while remaining photostable: it doesn't require additional stabilizers to maintain its effectiveness in sunlight. That's one of the reasons many consumers and clinicians prefer mineral sunscreen, especially for children, sensitive skin, and those looking to reduce exposure to certain chemical UV filters. Non-nano zinc is also safe for the surrounding coral reef, making it the kind of daily sunscreen you can build into a lasting skincare routine without a second thought — an easy foundation for sunscreen for daily use and a win-win decision as a business owner, a consumer, and an advocate for your island, without compromise.
Sunshine & Love,
Sarah Miller, CEO & Founder, EthoSun