The Essential Guide to Chemical vs. Mineral Sunscreen
If you haven’t heard it enough already: the best sunscreen is the one you will use. It’s true, wearing any sunscreen is better than nothing at all, and making it a part of your daily routine is a wise choice. It’s one of the best things you can use for skin cancer prevention, and is the most effective anti-aging product helping maintain the integrity of our precious collagen.
But the world of sunscreen is complex. Educational videos on social media showing best application practice or the different types of sunscreen are dime a dozen. Plus there’s a whole wide world of sunscreen products to choose from ranging from mass market to luxury that is constantly growing and evolving. Not to mention the battle between chemical vs. mineral sunscreen and questions around safety can get quite contentious. So amidst all of the noise, what do you need to know? Read on for the basics and some truths.
What’s the difference between chemical vs. mineral?
First things first, sunscreens are classified into two categories based on the type of UV filter (s) they contain – chemical and mineral. If we brush the world of beauty marketing aside, a traditional chemical sunscreen contains a combination of “organic” UV filters (think, avobenzone, homosalate, and octocrylene), and interestingly enough, these are categorized as organic because they contain carbon atoms (the basis of all organic matter). Chemical sunscreens are known to work by absorbing and converting UV light into heat within the skin, and they can be cosmetically elegant formulations.
Mineral sunscreens, on the other hand, feature “inorganic” UV filters such as Zinc Oxide (ZnO) and Titanium Dioxide (TiO2). These are metal oxides that are made up of metal and oxygen (they don’t contain carbon), and both ZnO and TiO2 typically have a white powdery consistency making them the biggest white-cast offenders. Mineral sunscreens work by forming a physical shield on the skin, scattering or reflecting UV light. There is however chatter on social media that mineral sunscreens also protect skin by absorbing UV rays like their chemical counterparts, but you should know that the data/science behind this is very limited.
It’s a question of safety…
We can’t ignore the elephant in the room when it comes to safety: chemical sunscreens. They are under a lot of heat right now and for good reason. There are newer studies that demonstrate that chemical sunscreens are systemically absorbed into the bloodstream leading to a FDA proposal in 2019 to re-evaluate the safety of organic UV filters, a process that is still ongoing. Inorganic UV filters ZnO and TiO2 found in mineral sunscreens, on the other hand, are the only FDA-approved ingredients for sunscreens that are considered GRASE (“generally recognized as safe and effective”). Keep in mind though – the verdict isn’t out regarding the safety of chemical sunscreens – so you don’t have to ditch them just yet. If you’re a clean beauty die hard then you probably wouldn’t take kindly to this advice.
There’s also concern around the eco-toxicity of chemical sunscreens harming our coral reefs. The key question remains: do the levels of organic UV filters found in the reef systems create what environmentalists call “environmental risk”? Currently, the answer is no because there is not enough scientific evidence to support this. We need more research and data. Having said that and based on the limited studies (as of today a total of 9 studies have investigated the toxicity of organic UV filters on coral) that have been conducted, regulators in states like Florida and Hawaii are likely taking precautionary measures by banning certain organic UV filters.
On the mineral side of things, there’s been controversy around ZnO in nanoparticle (i.e. tiny and fine) form created with the goal to improve the user experience of mineral sunscreens (e.g. lessen the white cast). But because of concerns involving skin penetration as well as environmental impact with nanoparticles, we’re seeing different technologies like premade micronized ZnO/TiO2 dispersions that also do a great job of ensuring that a mineral formula is more sheer and elegant. (FYI, iron oxides that are added to tint a sunscreen formulation can help offset the whiteness and offer visible light protection). You might have also noticed that product claims like “non-nano” and “reef-safe” are becoming more common. Both terms are unregulated, by the way.
So the question remains…which sunscreen is better? Safer? At this moment in time, it’s better to focus on what feels right to you. What works best for your skin. It’s worth worrying about the devil we do know for sure – there is well-established evidence that the sun’s UV rays can cause skin cancer and break down the skin’s collagen. So do your best to practice safe sun and join (only!) 15% of Americans that wear sunscreen daily.