Nanoparticles in Mineral SPF

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Here on the Pomp Beauty Blog, I have talked about the differences between chemical sunscreen and physical sunblock. In this blog, I want to dive a bit deeper into the potential risk with mineral sunblock and discuss whether mineral SPF is still the way to go.

As a recap there are two types of sun protection products: chemical; formulated with chemical sun-screening ingredients and physical; formulated with mineral sun-blocking ingredients. To learn more read Chemical SPF vs. Physical SPF

What are Mineral Sunblock Ingredients?

There are only 2 ingredients that are FDA-approved mineral sun-blocking ingredients. These ingredients are zinc oxide and titanium dioxide. Although both mineral ingredients protect against UVB rays equally (the rays that lead to sunburn), zinc oxide is particularly more protective when it comes to protecting your skin from UVA rays; (the rays that cause both aging and skin cancer). You want to make sure that your mineral SPF contains mainly zinc oxide, this makes it “broad-spectrum” and protects against both UVA and UVB rays.

Why Does Physical / Mineral SPF Leave a White Cast? It is Related to the Ingredient Size.

Mineral sunblocks are notorious for leaving behind a white cast and being difficult to blend into the skin, this is exactly why these ingredients are so protective from the sun’s rays and safe sunscreens to use. However, to make these products more enjoyable to apply and wear, manufacturers have begun shrinking the size of these mineral ingredients creating mineral micro and nanoparticles to make them blend easier. The smaller the particles the better they blend into the skin and the higher the SPF (UVB) protection, but the less UVA protection they offer. This means that product creators should be mindful of the size they make the particles, to not compromise their protective capability. Usually, this means a combination of larger zinc oxide particles for protection and smaller titanium dioxide particles to provide a more sheer appearance. 

It should be noted that although these mineral nanoparticles are unlikely able to be absorbed into the skin, the regulation of nanotechnology is very underdeveloped, and we simply do not know the effects of these nanoparticles on our skin or health yet. One thing we do know however is that nanoparticles can be inhaled into the lungs and can potentially cause organ damage. Particularly titanium dioxide, which is a known carcinogen when inhaled. That being said, it is best to avoid mists that contain nanoparticles, as well as powders and chapsticks, as these can be inhaled or ingested more easily than lotions.

Mineral SPF Still the Best and Safest Option

Although mineral sunblock may contain mysterious nanoparticles, chemical sunscreen ingredients still pose a greater risk as all their chemical ingredients can be absorbed into the skin and enter the bloodstream. Ingredients like oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate, should be avoided. Aerosol and spray sunscreens should also be avoided as there are added chemicals that are potentially toxic to your system. So mineral sunblock is still the safer choice, especially for those who have sensitive skin or are pregnant/nursing. Nanoscale titanium dioxide becomes transparent to visible light while serving as an efficient UV light absorber. Because the particle size is so small, nano-titanium dioxide does not reflect visible light, but does absorb UV light, enabling a transparent barrier that protects the skin from the sun’s harmful rays.  You should also be careful of nanoparticles in chemical sunscreens particularly in spray sunscreens as these are an even greater health risk. Unfortunately, the best and safest SPF is going to be a mineral sunblock of at least SPF 30 with no nano-particular technology and is difficult to blend into the skin. However, sun protection is always better than no sun protection and so the best SPF is the one you wear every day! 

Nicole Hatfield
Pomp Esthetician
NBC HWC & Certified Esthetician, Founder of Radiant Beings Wellness & Beauty Coaching