Though the importance of wearing sunscreen isn’t up for debate, the active ingredients used in sunscreen products certainly still are. One of the latest controversies surrounding sunscreen has to do with the nanoparticles found in mineral sunscreens.
Though mineral sunscreens such as zinc oxide are generally considered one of the safest and most effective sunscreens on the market, their association with nanoparticles has made some people question their safety. The general concern is whether or not nanoparticles can be absorbed into the skin, which research shows can have hormone-disrupting effects.
Enter non-nano zinc oxide, the active ingredient that blocks UV rays without the potential risks. What is non-nano zinc oxide, and why should you care?
Here are three things worth knowing about non-nano zinc oxide:
- Nanoparticles in mineral sunscreens are believed to be hormone disruptors, despite insufficient evidence to support this claim.
- Nonetheless, there are non-nano zinc oxide sunscreens and lip balms available to ease safety concerns.
- Zinc oxide offers several important skin health benefits.
Nanoparticles in Cosmetics—What’s the Concern?
To understand what non-nano zinc oxide is, you first need to know why some people are worried about nanoparticles. Zinc oxide, the active ingredient found in many mineral sunscreens, is often manufactured at nano sizes to boost its sun protective abilities and reduce the white residue it sometimes leaves on the skin.
One of the biggest concerns with nanoparticles is their potential to disrupt hormones. However, the long-held consensus by researchers has been that not enough nano zinc oxide is absorbed into the skin for this to matter.
What Does the Research Say?
The safety of zinc oxide was called into question after researchers published a study in Biomaterials demonstrating a potential link to cancer. In the 2011 study, researchers noted that zinc oxide activated a critical anti-tumor pathway which could stimulate DNA damage (see claim: “…in cells without robust p53, protective response can be tipped towards carcinogenesis when stimulated by DNA damage inducing agents like ZnO nanoparticles.”)
However, other published studies and reviews have come out refuting this possibility due to the fact that nanoparticles are rarely—if at all—absorbed into human skin. In a 2015 review published in the Archives of Toxicology, researchers found that the vast majority of nanoparticles remained on the outside of the skin (see claim: “All studies to assess dermal penetration of nanoparticles have unanimously concluded that the overwhelming majority of nanoparticles remain on the outer surface of the skin.”)
A more recent study published in the Journal of Investigative Dermatology found direct evidence that zinc oxide nanoparticles didn’t absorb into the human skin barrier, nor did they result in toxicity after multiple applications to human subjects (see claim: “…repeated application of ZnO-NPs to the skin…no evidence of ZnO-NP penetration into the viable epidermis nor toxicity in the underlying viable epidermis.”)
To sum it all up, more studies on human models are needed to back up claims that nanoparticles in zinc oxide compromise the public’s safety. While we wait for more studies, there has been one skin care ingredient which has shown to be a promising alternative: Non-nano zinc oxide.
What is Non-Nano Zinc Oxide?
Non-nano zinc oxide sunscreens are manufactured with different particle sizes (typically, over 100nm) and shapes compared to their nanosized counterparts, making them—in theory—a safer and more effective solution to our sun safety dilemma.
Non-nano zinc oxides aren’t without their problems—namely, they can sometimes leave white residue on the skin. You may need to shop around to find a non-nano zinc oxide product that won’t leave white streaks on your skin.
Even if you prefer your chemical sunscreens over physical blockers, you may want to consider looking for a non-nano zinc lip balm. The reason for this is simple: Though most research currently suggests that zinc oxide isn’t absorbed into the skin, you can accidentally ingest the active ingredient or inhale its fumes by putting it on your lips.
Take the skin care quizIs Zinc Oxide Good for Your Skin?
Despite the controversy surrounding nanoparticles in zinc oxide, the ingredient itself isn’t necessarily bad. In fact, the opposite is true: Zinc oxide can offer a wide range of skin benefits.
For example, zinc oxide has been used successfully to treat eczema, a skin condition which affects around 10 percent of the worldwide population.
In a 2013 study published in Clinical, Cosmetic and Investigational Dermatology, researchers concluded that zinc oxide textiles were an effective treatment for atopic dermatitis, also known as eczema (see claim: “We observed a rapid improvement of AD severity, pruritus, and subjective sleep quality when AD patients wore the ZnO textiles overnight for 3 consecutive days…”)
Zinc oxide has also been used to treat acne and minor burn wounds. Basically, you shouldn’t write off zinc oxide as a skin care ingredient entirely. It all depends on how it’s manufactured.
Does Zinc Oxide Protect Against UVA and UVB Rays?
Zinc oxide is one of the few ingredients used in sunscreens that offers effective protection against both UVA and UVB rays. For this reason, mineral zinc sunscreens are some of the most highly rated on the Environmental Working Group website.
UVA rays are associated with premature aging, while UVB rays are associated with melanoma, the most-deadly form of skin cancer. By wearing a broad spectrum mineral sunscreen, you can lower your risk of melanoma and keep wrinkles at bay for longer.
How Much Zinc Oxide Do You Need in Sunscreen?
Those who want to make homemade sunscreen with zinc oxide often wonder how much they need to add to achieve an adequate sun protection factor (SPF). This method isn’t recommended because the only way to be certain of any product’s SPF is through clinical testing.
Choosing the Best Sunscreen for Your Skin
If you find yourself skipping your sunscreen because it leaves behind white residue, there is nothing wrong with sticking to your daily moisturizer with SPF. Since your lips are a place where nanoparticles are most prone to accidental ingestion, consider reserving the non-nano zinc oxide for your lip balm.
Ultimately, it’s important to make the decision that feels right to you. While you wait for more research to become available on non-nano zinc oxide, feel free to check out the rest of our skin care blogs or try one of Tiege Hanley’s skin care systems for yourself.
