Mineral vs Chemical Sunscreens
There are several differences between mineral and chemical sunscreens, and while the main concern with chemical sunscreens is nanoparticles, even mineral sunscreens, if small enough can be classified as nano particles. So what is the big deal?
Several scientific papers have shown that chemical nanoparticles absorb through the skin and into the bloodstream, (Journal of American Medical Association May 2019). In addition, this study found that chemical sunscreen nanoparticles can be found in the bloodstream days after cessation of product application. This means that if you apply a chemical sunscreen, it will absorb through the skin into your bloodstream and stay in your body for days before your body will eliminate it. And while there is no definitive data suggesting that the nanoparticles have harmful effects while in your body, I’m of the opinion that there is no reason to add additional unnecessary chemicals into our bloodstream.
Lets look at some differences between chemical and physical sunscreens; Chemical sunscreen particles are so small (nano particles) that they penetrate through the skin and absorb into the blood stream. This absorption can cause skin irritation and this is how these nanoparticles also damage coral reefs. As chemical sunscreen absorbs into our body, it also absorbs the sun’s UVA and UVB rays. Mineral sunscreens on the other hand stay on top of the skin surface and reflect the sun’s rays like little mirrors. Because they are not absorbed, they tend not to cause skin irritation.
Chemical sunscreens also have shorter ranges of light wavelength absorption so several chemical sunscreen actives need to be combined in a formula to ensure broad spectrum of protection. For example, the wavelength range for Avobenzone is 340-385 nm (UVA spectrum) and oxybenzone 290-320nm (UVB spectrum). Mineral particles on the other hand, have much wider ranges of light wave reflection. Zinc oxide for example, covers a wide range of light from 280-400 nm (long & short UVA and UVB spectrum), thereby making it easier to create broad spectrum protection. Titanium Dioxide protects from both UVA and UVB, although it does not cover long UVA rays.
Traditionally, the problem with physical sunscreens has been the unattractive white cast left on the skin after application, whereas chemical sunscreens produce a nice colorless finish. However, times have changed and the most modern sunscreen technologies use encapsulation and coating techniques which “cover up” the natural white color that mineral sunscreens have, thereby eliminating the well known “white cast”. The addition of iron oxides to formulations has also resulted in a natural iron/rusty hue that neutralizes any white cast, resulting in a more natural finish.
For this reason, mineral formulations are becoming more appealing once again. Sophisticated technology used in modern formulations usually comes with a higher price tag compared to standard “white-cast” formulation counterparts. This is because sophisticated, elegant formulations offer much more than just a nice color and the typical UVA/UVB protection. Other factors to take into account when choosing a sunscreen include the availability of protection from infrared light, HEV (hight energy visible light also known as blue light which is generated from electronic screens), pollution, infrared generated free radicals, and additional hydrating ingredients such as niacinamide and hyaluronic acid. This is why these formulations benefit the skin even on cloudy, rainy days and days when you will be indoors staring at a computer screen all day long.
Modern, medical grade sunscreen formulations provide protection from pollution/free radicles and a wide variety of light rays, beyond the standard UVA/UVB spectrum, without unnecessary nanoparticles or “white cast” finish on the skin.
*These are my personal and professional opinions and are not associated with any sponsorships or promotions. If you have concerns related to your skin or skin reactions to these products, my blog should not replace medical attention so please seek the advice of your medical doctor, who can examine, assess and speak with you in person.