3. SHOULD I CHOOSE A MINERAL OR CHEMICAL SUNSCREEN?
There are two big reasons why you should avoid using sunscreens containing chemical filters:
a) They can be damaging to human health
The fact is that chemical sunscreens are absorbed through human skin at a higher rate than previously believed. We now know that several chemical filters have been linked to allergic skin reactions and hormone disruption in children and adults. The most alarming is oxybenzone, which not only causes allergic skin reactions but lab studies have shown that oxybenzone is causing disruptions to hormonal balance.
In 2019 the US Federal Drug Administration (FDA) declared only 2 out of 16 available sunscreen actives as GRASE (“generally regarded as safe and effective”). These two were the mineral filters zinc oxide and titanium dioxide. FDA stated: “there are insufficient safety data to make a positive GRASE determination for the remaining 12 ingredients at this time”
In 2019 and 2020, FDA published two studies showing that the ingredients oxybenzone, octinoxate, octisalate, octocrylene, homosalate, and avobenzone are systemically absorbed into the body after a single use (Matta 2019, Matta 2020). The FDA also found that the chemical sunscreen ingredients could be detected on the skin and in the blood weeks after the application. (Matta 2020)
b) They can be damaging to aquatic life
Now let’s consider the health of our planet. As National Geographic reports, 14,000 tons of sunscreen enter waters, and coral reefs are dying because of this. This phenomenon is called coral bleaching.
The biggest culprits are the chemical sun filters oxybenzone and octinoxate. But other chemical sun filters, as well as parabens, retinyl palmitate, and fragrances can all disturb aquatic life. Although coral reefs cover less than 1% of the ocean floor, they support nearly 25% of all marine life. Their health is central to the functioning of aquatic ecosystems.
Due to the increasing evidence against chemical sun filters, the state of Hawaii decided in 2018 to ban the sale of sunscreen products containing the chemical filters oxybenzone and octinoxate by 2021. In 2019 the same ban was passed in the Florida state senate.
Other reasons for choosing mineral sunscreens over chemical ones relate to their mode of action: physically blocking UV rays. This makes mineral sunscreens naturally broad-spectrum because they reflect both UVB and UVA rays from the skin’s surface.
Chemical sunscreen typically take 20 to 30 minutes to absorb into the skin, mineral sunscreens offer immediate protection — no waiting needed. Lastly, mineral filters do not convert UV rays into heat as chemical filters do. Mineral sunscreens are therefore ideal for children, people with sensitive skin, and people with rosacea or melasma. The heat dissipation of chemical sunscreens can exacerbate rosacea and melasma and inflame sensitive skins.
4. WHAT IS MEANT BY NANO OR NON-NANO, UNCOATED OR COATED?
Many clean and natural beauty brands have started writing that their sunscreens use non-nano, uncoated minerals. What does this mean exactly?
A nanoparticle is defined as a particle smaller than 100 nanometers in diameter. The nanoparticle controversy stems from the potential health risks caused by nanoparticles if they were to enter the human body. The biggest concern with nanoparticles in cosmetics is the threat of inhalation when they are used in powders and sprays.
This is not a concern when particles like zinc oxide are dispersed in a cream or lotion base. Studies have shown that very small nanoparticles (smaller than 35nm) of zinc oxide and titanium dioxide can be harmful to the environment by being toxic to marine life. For this reason, it is best to always look for non-nano-sized mineral filters in sunscreens.
Many brands use titanium dioxide and zinc oxide particles that have been coated with an inert substance to make them easier to mix with the other ingredients. In the case of titanium dioxide, the coating is used to make the particles less photoreactive. The EU requires nano-titanium dioxide particles to be coated otherwise, they react with UV light and release oxidative radicals that can damage the skin.
EU does not require any external coating on nano or non-nano ZnO particles since ZnO does not show this photo-catalytic activity. If you wish to avoid the extra chemicals, it’s best to choose non-nano or sunscreen with uncoated mineral particles.
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