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What Is Mineral Sunscreen? How It Works, Why It’s Better and How to Choose the Best Formula to Protect Your Skin

Make the switch to mineral.
What is mineral sunscreen

Is your SPF as safe and effective as it should be? Maybe not, if you’re using a type of sunscreen that contains what are known as “chemical” instead of mineral active ingredients.

Although chemical-based formulas comprise the majority of sunscreens on the market, a growing body of research has found that these filters can absorb into the bloodstream at alarming rates, and are linked to hormonal disruption.

What’s more, recent laboratory testing of sunscreens on the US market has found that most sunscreens don’t even meet their own protection claims, especially against UVA—leaving you vulnerable to sunburn, skin cancer and premature aging.[1]

In contrast, mineral formulas have no such safety concerns, and as long as you know what to look for on labels, are in fact the most effective options available to us here in North America.

With this tutorial, you will learn why mineral sunscreens are the best choice for your skin, what to look for when choosing a product, and my favourite formulas to try.

I’ve also got a free checklist for you to download at the end of this article!

What Is Mineral Sunscreen?

How Does Mineral Sunscreen Work?

Mineral Sunscreen Does Not Reflect UV Light

“Consumers are blitzed with the fallacy that ‘natural’ (mineral) filters reflect or bend light like a barrier—whereas the so-called chemical agents absorb light in a chemical reaction,” he explains. “[But] photoprotection from scattering or reflection of light occurs only if a very thick optical barrier prevents light from passing through to the skin, similar to a thick coat of paint not seen in commercially available sunscreens. This would not be acceptable to any consumer.”[2]

In other words, if mineral sunscreens were truly formulated to reflect UV, they’d be so thick, heavy and unappealing that nobody would wear them.

Mineral Sunscreen Absorbs UV Light

So, how do the mineral sunscreens on the market really work? 

“All mineral or insoluble UV filters act as semi-conductors and absorb photons with electron shifts to a different valence band,” says Dr. Dudley. “So a harmful wavelength is converted to a less harmful or innocuous wavelength.”[2]

That means mineral sunscreen is just like “chemical” sunscreen in how it protects. Contrary to popular belief, all sunscreens work the same way, by absorbing harmful UV rays before they can inflict serious damage.

However, there are some key reasons why mineral sunscreen is both a safer and more effective choice, which we’ll get into next.

Is Mineral Sunscreen Better?

✓ Mineral Sunscreen Does Not Absorb Into the Body

The first thing you need to know about mineral sunscreen is that it doesn’t penetrate your skin. “This is our first precept of safety,” says Dr. Sharyn Laughlin, co-founder of The Sunscreen Company. “Filters that are large in molecular weight and are insoluble do not penetrate skin and achieve blood and tissue levels, bind to brain receptors, cross the placenta to the fetus, and enter breastmilk.”

Rather than the terms “chemical” versus “mineral,” a more accurate way to think about sunscreens is soluble versus insoluble:

  • Soluble sunscreen filters penetrate your skin, due to their small particle sizes, and absorb into your body. These include cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone, oxybenzone and avobenzone. Notably, all of these filters were delisted in 2019 by the US Food and Drug Administration. Based on a lack of safety data regarding their absorption into the body and the long-term effects, they are no longer designated as “GRASE” (Generally Recognized As Safe and Effective).[3]
  • Insoluble sunscreen filters do not penetrate your skin, due to their large particle sizes, and therefore cannot absorb into your body. These include zinc oxide and titanium dioxide, plus the “chemical” filters Mexoryl SX (ecamsule or terephthalylidene dicamphor sulfonic acid) and Mexoryl XL (drometrizole trisiloxane). However, as L’Oréal patented ingredients, Mexoryl SX and XL can only be found in combination with the undesirable soluble filters.

⚠️ Outside of North America, you can also find these insoluble filters, which act like minerals: Tinosorb A2B (tris-biphenyl triazine), Tinosorb M (bisoctrizole or methylene bis-benzotriazolyl tetramethylbutylphenol) and Tinosorb S (bemotrizinol or bis-ethylhexyloxyphenol methoxyphenyl triazine). In the US, none of these are approved by the FDA. In Canada, Tinosorb M and Tinosorb S are approved by Health Canada, but only allowed in low concentrations compared to other jurisdictions. 

✓ Mineral Sunscreen Does Not Cause Hormone Disruption

Unlike the soluble chemical filters, mineral sunscreens do not interfere with your body’s natural hormone production.

“A 2016 review of 85 scientific papers in humans and lower species concluded that [soluble] hydrocarbon UV filters are generally involved in the disruption of the hypothalamic–pituitary–gonadal system,” Dr. Laughlin explains.[4]

“More recent studies in 2018 and 2019 confirm that [they] clearly change levels of virtually every sex hormone, pituitary hormones, thyroid hormones and certain growth factors in both pregnant and non-pregnant women.”[4]

✓ Mineral Sunscreen Gives Superior UVA Protection

Sunscreen FilterUVAUVB

Avobenzone

● Extensive protection

◔ Limited protection

Cinoxate

◔ Limited protection

● Extensive protection

Dioxybenzone

◕ Considerable protection

● Extensive protection

Ecamsule

● Extensive protection

◔ Limited protection

Ensulizole

○ Minimal protection

● Extensive protection

Homosalate

○ Minimal protection

● Extensive protection

Meradimate

◕ Considerable protection

● Extensive protection

Octinoxate

◔ Limited protection

● Extensive protection

Octisalate

○ Minimal protection

● Extensive protection

Octocrylene

◔ Limited protection

● Extensive protection

Oxybenzone

◕ Considerable protection

● Extensive protection

Padimate O

○ Minimal protection

● Extensive protection

Sulisobenzone

◕ Considerable protection

● Extensive protection

Titanium Dioxide

◕ Considerable protection

● Extensive protection

Zinc Oxide

● Extensive protection

● Extensive protection

As you can see in this chart, most chemical sunscreens are “UVB-biased.”[5] In other words, they do a good job of filtering out the UVB rays that cause sunburn, but are inadequate against the more damaging UVA rays that trigger skin cancers and premature skin aging. This is particularly troubling because UVA accounts for up to 95% of the UV light that reaches our skin.[6] (See my UVA and UVB tutorial to learn more.)

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From The Skincare Edit Archives

Fortunately, mineral sunscreens don’t have this problem. Zinc oxide is the only approved filter that gives you extensive protection against both UVA and UVB.

Titanium dioxide offers the same extensive protection against UVB, but isn’t as effective against UVA. For this reason, it should always be combined with a stronger UVA filter, like zinc oxide.

✓ Mineral Sunscreen Won’t Irritate Sensitive Skin

Mineral sunscreens are even recommended by the American Academy of Dermatology to anyone who has sensitive skin.[7] That’s because “chemical” filters (including oxybenzone, avobenzone and octocrylene) have been linked to dermatitis and allergic skin reactions.[8][9][10]

What to Look for in a Mineral Sunscreen

1. Is It SPF 30 or Higher?

Sunscreen FilterMaximum SPF Units Per 1%

Titanium Dioxide

SPF 2.6

Zinc Oxide

SPF 1.6

As any dermatologist will tell you, we all need to be using at least an SPF 30 for broad-spectrum protection. 

The problem is, SPF numbers on labels may not be accurate. A recent investigation of 51 sunscreens with SPF values from 15-110 found that they were on average only 42-59% of the labelled SPF.[1] Dr. Dudley also refers to another study where out of 50 sunscreens labelled SPF 50 or higher, all were only SPF 6-10 when measured in sunlight.[11] 

Why the discrepancy? Because SPF does not accurately estimate a sunscreen’s actual performance in sunlight, and furthermore, readings can be manipulated by adding anti-redness agents and SPF boosters (like bisabolol, niacinamide and salicylate compounds).[11]

Fortunately, if you know your sunscreen’s concentration of active ingredients, you can estimate its SPF number on your own using data from the industry’s sunscreen simulation tools.[12][13]

For every 1% of each active ingredient, you get a certain amount of SPF units. As you can see in the chart above, 1% zinc oxide gives you 1.6 SPF units, while 1% titanium dioxide gives you 2.6 SPF units. So let’s say you have a formula with 20% zinc oxide. That works out to SPF 32—an ideal SPF number. A formula with 15% zinc oxide and 5% titanium dioxide works out to SPF 37.

2. Does It Contain at Least 15% Zinc Oxide?

Now, are there certain minimum percentages of active ingredients that you need to look for to ensure you are sufficiently protected?

Absolutely. “For the North American consumer, it comes down to zinc oxide at a concentration of at least 15% as the best filter to protect against UVA,” says Dr. Laughlin.

That means you’ve got two options:

  • 20-25% zinc oxide: Since it gives you extensive protection against both UVA and UVB rays, zinc oxide alone can be the sole active ingredient in your formula. Look for a concentration of at least 20% up to the maximum of 25%.
  • 15-20% zinc oxide + >5% titanium dioxide: Alternatively, you can combine zinc oxide with titanium dioxide to get broad-spectrum UVA and UVB protection. To go with your minimum 15% zinc oxide, Dr. Dudley recommends looking for at least 5% titanium dioxide.[14]

3. Is It Low in PUFAs, Fragrance and Silicone?

With all skincare products—not just sunscreen—I recommending limiting or avoiding potentially irritating or comedogenic ingredients. The main three are:

  • PUFAs: Polyunsaturated fatty acids (PUFAs) are volatile, unstable fatty acids that are highly susceptible to oxidation in the presence of heat and light. (And with sunscreen, you’re getting lots of both!) When PUFAs oxidize, they generate free radicals, which are a major cause of skin aging and cellular damage. I look for sunscreens without PUFA-based oils in the first five ingredients, which typically represent about 80% of a product. 
  • Fragrance: Since fragrance compounds—whether synthetic or natural—are the number one trigger for irritations from personal care products, your skin will be happiest if you steer clear of them. Go for either fragrance-free formulas or products that list fragrance at the end of their ingredients lists. 
  • Silicone: Although they have no bearing on sunscreen safety, silicones create “slip” and a smooth finish by forming a film on top of your skin. Unfortunately, this can trap acne-causing debris in your pores and interfere with your skin’s natural renewal processes. That’s why I choose sunscreens without silicones in the first five ingredients.

The Best Mineral Sunscreens for Your Skin

Kinship Self Reflect Probiotic Moisturizing Sunscreen Zinc Oxide SPF 32
EleVen by Venus Williams Unrivaled Sun Serum SPF 35
Pipette Mineral Sunscreen SPF 50
First Aid Beauty Mineral Sunscreen Zinc Oxide Broad Spectrum SPF 30
EltaMD UV Glow Broad-Spectrum SPF 36
Salt Stone Lightweight Sheer Daily Sunscreen SPF 40
REN Clean Skincare Clean Screen Mineral SPF 30 Mattifying Face Sunscreen
Ghost Democracy Invisible Lightweight Daily Sunscreen SPF 33
CyberDerm Simply Zinc Lite Untinted Transparent Sunscreen Lotion SPF 50
Odacite Sun Guardian Oceanic Glacial Water Day Creme SPF 30

Conclusion + Free Checklist

Now you have all the information you need on how mineral sunscreen actually works, and how to get the best possible protection for your skin. 

It’s a lot to remember—which is why I created the How to Choose a Sunscreen Checklist. Just click below to download it so you have a handy reference when checking sunscreen ingredients lists. (It’s FREE!)

How to Choose a Sunscreen Download

Clearly, there’s more to finding a good sunscreen than just making sure the product contains mineral active ingredients. 

You also need to ensure you’re properly shielded from UVA and UVB—especially UVA, since it comprises the vast majority of UV rays and is the most damaging.

With these tips for choosing a truly broad-spectrum mineral sunscreen, you’ll be able to do just that, and stay protected from sunburn, skin cancer and skin aging.

Further Reading

  1. Andrews, David Q., Rauhe, Kali, Burns, Carla, Spilman, Emily, M Temkin, Alexis M., Perrone-Gray, Sean, Naidenko, Olga V. & Leiba, Nneka. (2022). Laboratory testing of sunscreens on the US market finds lower in vitro SPF values than on labels and even less UVA protection. Photodermatology, Photoimmunology & Photomedicine. 2022 May; 38(3): 224-232.
  2. Dudley, Denis. (2018, June 21). Sun Protection Myths: Facts Versus Fiction. The Sunscreen Doc.
  3. Food and Drug Administration. (2019, February 26). Sunscreen Drug Products for Over-the-Counter Human Use. Federal Register.
  4. Hilton, Lisette. (2019, July 16). Studies don’t change sunscreen guidance. Dermatology Times.
  5. Faure, Bertrand, Salazar-Alvarez, German,  Ahniyaz, Anwar, Villaluenga, Irune, Berriozabal, Gemma, De Miguel, Yolanda R. & Bergström, Lennart. (2013). Dispersion and surface functionalization of oxide nanoparticles for transparent photocatalytic and UV-protecting coatings and sunscreensScience and Technology of Advanced Materials. 2013 Apr; 14(2): 023001.
  6. UV Radiation & Your Skin. Skin Cancer Foundation. 
  7. Sunscreen FAQs. American Academy of Dermatology Association. 
  8. Collins, P. & Ferguson, J. (1994). Photoallergic contact dermatitis to oxybenzone. The British Journal of Dermatology. 1994 Jul; 131(1): 124-9.
  9. Beach, Renée A. & Pratt, Melanie D. (2009). Chronic actinic dermatitis: clinical cases, diagnostic workup, and therapeutic management. Journal of Cutaneous Medicine and Surgery. May-Jun 2009; 13(3): 121-8.
  10. de Groot, Anton C. & Roberts, David W. (2014). Contact and photocontact allergy to octocrylene: a review. Contact Dermatitis. 2014 Apr; 70(4): 193-204.
  11. Dudley, Denis. (2017, October 23). The Label SPF Cannot Be Used to Estimate Safe Sun Exposure Time. The Sunscreen Doc.
  12. BASF Sunscreen Simulator.
  13. DSM Sunscreen Optimizer.
  14. Dudley, Denis. (2020, March 13). Reef “Safe” or Reef “Friendly” Sunscreens. The Sunscreen Doc.

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