UVA vs UVB
An SPF product should protect from both UVA and UVB rays. But did you know that the FDA doesn’t require UVA protection? This is one of those times when reading labels is important; it’s up to you to make sure your product provides both. UVA refers to the wavelengths of sunlight that cause photoaging, UVB refers to rays of light that cause the burn. A good way to remember is uvA for Aging and uvB for Burn.
The good news is natural sunscreen ingredients including zinc and titanium protect from both UVA and UVB overexposure, so look for one or both of those ingredients.
Mineral vs Chemical Ingredients in Safe Sunscreen
A natural mineral (aka physical) block is, by far, the safest option to get your SPF. The minerals zinc and titanium sit on the skin’s surface and reflect sunrays out away from the body like tin foil. Chemical ingredients are absorbed into the skin to deal with sunrays in a chemically reactive process in the skin cell itself, with potentially unintended and harmful consequences to the skin and body.
Chemical sunscreen ingredients such as Aminobenzoic Acid, Octyl Methoxycinnamate (OMC), Ethylhexyl p-Methoxycinnamate, Cinoxate, Dioxybenzone, Homosalate, Octocrylene, Octinoxate, Octisalate, and Oxybenzone are designed to work within the cells of the body. Most manufacturers continue to use these ingredients despite higher incidents of contact irritation to the skin and known adverse effects on the body systems because they are inexpensive, invisible on the skin, and easier to formulate.
Once these chemicals have done their job, the body must expend extra energy to eliminate them and any byproducts. This is unnecessary with natural sunscreen ingredients. Most chemical sunscreens protect only against UVB ray damage. More alarming is the fact that many of chemical sunscreen ingredients mimic estrogens (xenoestrogens) and may cause hormone-related developmental problems in young children.
And now…a little chemistry lesson: Nanoparticles
As you increase your awareness of safety issues related to the skincare ingredients, you will probably run into warnings about nanoparticles – which some personal care product manufacturers use and can represent a potential health hazard. Nanoparticles, particularly those of metallic ingredients, are so small that they are able to pass through the wall, or membrane, of cells in the body and into the bloodstream. Medical science does not yet fully understand the complications and risks associated with nanoparticles but it has been linked to liver damage, Alzheimer’s and other health problems.
Because mineral-based sunscreens use metals such as Zinc and Titanium as the active ingredient, it is helpful to understand that a particle of nano size is not the same thing as a nano particle.
A nano particle is any particle less than 100 nanometers in diameter (across). This can be confusing as a nano-sized material is not necessarily a nanoparticle. For example, a bulk ingredient material that has been reduced to 500 nanometers is NOT a nanoparticle because it is 5 times larger than 100 nanometers. As a point of reference, a particle must be less than 50 nanometers (a nanoparticle) to enter skin cells; less than 70 nanometers to enter the lungs.
Trying to fit a 100 nanometer particle into the skin cell membrane is like trying to force a baseball through a hole the size of a ping-pong ball. It is physically impossible. So, when choosing a chemical-free sunscreen, it is important to ensure that the manufacturer does NOT use nanoparticles of zinc or titanium.