Sunscreen: The Ins and Outs

By on June 5, 2017, in Beauty Knowledge Center, Cosmetics, Skincare, Soft Surroundings

By Soleil Toujours Founder, Valerie McMurray

Valerie’s breakthrough chemical-free mineral formulations pair powerful anti-agers and antioxidants with the world’s finest natural and organic ingredients to deliver complete UVA and UVB protection in a sheer veil of radiance suitable for all skin tones.

Nine years ago, when I was pregnant during the summer with my third child, I started becoming very concerned with the safety of sunscreen. Pregnancy always heightened my awareness about the products I put on my skin. The skin is a sponge, so what you put on it absorbs into the skin and potentially enters the blood stream and even the fetus’ blood. After doing a bit of research and unable to find great feeling, non-chalky and safe sunscreen products, a sunscreen business was born. But to understand which sunscreens are best for you, here’s a bit of background to help you make the right decision.

UV Rays Explained:

First, it’s important to understand UV rays and why we need to protect against them. There are two types of UV rays that we care about as they penetrate the ozone layer and cause damage to the skin: UVA rays and UVB rays. The third type of ray, UVC rays, do not penetrate the ozone, so we are only concerned with UVA and UVB rays. UVA rays penetrate the layers of the skin and are responsible for premature aging. UVB rays cause tanning and burning on the upper layers of the skin. Both UVA and UVB rays can cause skin cancer, so it is important to always use a product with broad spectrum protection (protects against both UVA and UVB rays). One in 5 Americans is diagnosed with skin cancer every year. It’s truly an epidemic and one that can be avoided with the right protection. Furthermore, the sun is responsible for approximately 80% of premature aging of the skin, yet another reason to wear sunscreen. Finally, UVA rays can penetrate clouds and glass, so you are still exposed while driving or on a cloudy day – UVB rays do not penetrate glass and clouds. On the whole, it’s important to wear sunscreen daily. Now, let’s look at what sunscreens are most suitable and what the different types there are. There are 2 types of sunscreens: physical or mineral and chemical sunscreens – both work in very different ways.

Physical/Mineral Sunscreens:

 Physical sunscreens use UV filters either Zinc Oxide and or Titanium Dioxide. These filters reflect, scatter and block the sun’s rays from the surface of the skin. Zinc Oxide and Titanium Dioxide work by forming a shield over the skin and reflecting UV rays, like how a mirror reflects light. When UV rays hit the skin, they bounce off this ‘mirror’ which inhibits penetration into the skin. In reality, full deflection does not happen, as some rays invariably get through. On the positive side, both Zinc Oxide and Titanium Dioxide are safe and very stable in formulas and when exposed to the sun. They are not absorbed by the skin (unless in nanoparticle form), and therefore do not cause reactions. They are great choices for people with sensitive skin or for children. In fact, Zinc Oxide is also an anti-irritant and skin protectant, and is commonly used in sensitive skin care lines. Zinc Oxide and Titanium Dioxide are sourced from minerals that are found in nature. Zinc oxide is the only ingredient approved by the FDA that effectively protects against both UVA and UVB rays. Titanium Dioxide is used for its UV-reflective properties and for its ability to remain stable when exposed to UV rays. Unlike many chemical UV filters, Titanium Dioxide does not degrade in the sun. Finally, p hysical sunscreens work as soon as you put them on. On the negative side, mineral sunscreens can sometimes leave a white cast on the skin and be quite thick and difficult to rub in. With modern technology, there are more cosmetically elegant formulas that have micronized these mineral particles to minimize the white cast. Micronization means the particle size has been made much smaller, but larger than 100nm. Zinc Oxide and Titanium Dioxide can further be reduced to nano-sized particles (15-100 nm) and these nanoparticles leave no white deposit. When in nanoparticle form, they absorb UV rays (rather than reflect them). The safety of nanoparticles, however, is up for debate as some believe nanoparticles can penetrate the skin and enter the blood. European countries require that sunscreen labels indicate whether nanoparticles are present. Also, the more micronized the particles, the thinner the ‘shield’ and the less protected you are. Larger particle sizes protect better, but they make skin appear whiter. Research on the potential health impacts of nanoparticles is ongoing, so the verdict is still out.

Chemical Sunscreens:

 The second type of sunscreen is a chemical sunscreen. Chemical sunscreens use active ingredients that work by penetrating the skin and absorbing the energy of the sun’s rays like a sponge and converting it to heat that is dispersed in the skin. While all physical UV filters block from both UVA and UVB rays, most chemical UV filters protect one or the other, not both. Chemical ones require about 20 minutes to fully sink in and they also tend to be more irritating to the skin, since multiple ingredients must be combined to get broad spectrum coverage. Some chemical filters are known to cause contact and irritant dermatitis and photosensitivity. In addition, some chemical sunscreens can cause free radical formation, which leads to more sun damage in the long run; the ideal combination is supplementation with antioxidants to help scavenge free radicals. Finally, some sunscreen chemicals are known to cause viruses in coral reefs, killing up to 10% of the world’s coral communities. Some of the most common chemical filters are:

  • Avobenzone – has the best UVA protection. The EWG (Environmental Working Group) notes it has limited skin penetration and no evidence of hormone disruption, however, it is very unstable and degrades in sunlight.
  • Oxybenzone – has one of the highest penetration percentages in lab studies (1-9%) and acts like estrogen. It has been associated with endometriosis in women and was named allergen of the year in 2014 by the American Contact Dermatitis Society.
  • Octinoxate – has been found in mother’s milk and mimics hormonal activity, which may cause disruptions.
  • Octisalate – Usually added to help stabilize Avobenzone, Octisalate is unlikely to cause allergic reactions according to the EWG.
  • Octocrylene – may cause allergic skin reactions in sensitive individuals.
  • Homosalate – a weak hormone disruptor, and sunlight breaks down the chemical into harmful byproducts. On the positive side, chemical sunscreens are more elegant, sheer and lightweight in application. They often come in a convenient continuous mist format that is easy to use and doesn’t require much rubbing in. The downside of this convenience, other than some of the potentially harmful effects chemicals can cause, is that often one can miss a spot on the body and end up getting sunburned. Careful application and reapplication helps to mitigate this.


After learning the above, you’re either in camp mineral – where you prefer the sometimes (but not always) thicker formulas that can leave a white cast on the skin that contains active mineral ingredients Zinc Oxide and/or Titanium Dioxide (which are naturally broad spectrum, meaning they protect against both UVA and UVB rays) and work by sitting on top of the skin and deflecting the sun’s rays. Or, you’re in camp chemical – opting for the lighter weight clear formulas that penetrate the skin and absorb the sun’s rays like a sponge. You may also find some great formulas that are a combination of both mineral and chemical, taking advantage of the positives of both types of UV filters. Wherever you may fall, it’s important to remember that sunscreen is one of the most vital steps in your daily skincare regime. Apply enough sunscreen to cover all exposed areas, especially those often overlooked such as the back of the neck, ears, neck and décolleté, which are particularly susceptible to sun damage and reapply as often as needed and at least every two hours when exposed to the sun for extended periods. Don’t forget your hat, sunglasses, staying out of the sun during peak sun hours and wearing long sleeves to further help your skin stay healthy. Here’s to practicing safe sun! Cheers!