Zinc Sunscreens: How They Work and Why To Use Them
Everything You Need to Know About Zinc Sunscreens
There are so many types of sunscreen available that choosing one can be seriously confusing. Zinc-based sunscreens have gained significant popularity in recent years. In this blog post, we'll explore how zinc sunscreens work, their advantages over other types, and why you should use them in your sun protection regimen.
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Zinc Oxide in Sunscreen
Zinc oxide is a mineral compound derived from zinc, which is a naturally occurring element. Zinc is added to a sunscreen formulation to provide broad spectrum protection against UVA and UVB rays.
For most people, zinc conjures up images of surfers and cricket players with a white layer of sunscreen smeared thickly across their face. Thankfully, it is possible to make a zinc sunscreen that doesn’t leave the white cast on your skin (which is exactly what we have done).
How Zinc Oxide Sunscreen Works
Unlike chemical sunscreens that absorb UV radiation, zinc oxide physically sits on top of the skin, forming a thin layer. When UV rays hit this layer, the zinc works as a filter protecting the skin primarily via absorption of UV radiation (Cole et al. 2016). This is contrary to popular belief that mineral sunscreens protect against the sun by physically blocking, reflecting or scattering UV rays. This is one of the reasons the term ‘sunblock’ is falling out of fashion (because the term ‘sunblock’ implies physically ‘blocking’ the rays - learn more about sunscreen versus sunblock).
Our Sunscreen Rubs in ClearZinc has long been used by hardcore outdoors people for its superior sun protection qualities. Traditionally, it's made into a thick paste which stays on for hours in the water or when sweating and as well as protecting against UV rays, it also creates a physical barrier trapping moisture and protecting against salt and wind. However, having the white ghost look isn’t for everyone. Few people want a thick white paste smeared on their face and body when sunbathing or applied under makeup on a daily basis. That's why we expertly formulated a zinc sunscreen that rubs in well and doesn't leave a white cast.
Are nanoparticles safe in sunscreen?
Firstly, what on earth are nano-particles? They are ultra-fine particles of zinc or titanium dioxide that are added to sunscreens to provide SPF protection. Nano particles are smaller than non-nano zinc (non-nano zinc is what we use in our sunscreen).
Zinc oxide is a common ingredient in 'natural sunscreen' but concerns have been raised about the safety of its nanoparticle (NP) form.
Drawing on the best available evidence, sunscreen containing nanoparticles appears to be safe and do not pose a risk. However, we continue to monitor research.
“Repeated application of ZnO-NPs to the skin, as used in global sunscreen products, appears to be safe, with no evidence of ZnO-NP penetration into the viable epidermis nor toxicity in the underlying viable epidermis” (Mohammed et al. 2019).
While research shows that zinc nanoparticles do not penetrate the skin there is some evidence that titanium dioxide nano-particles may be absorbed systemically Adler and DeLeo (2020). Titanium dioxide is another mineral UV filter commonly used in natural sunscreens. We do not use titanium dioxide in our products.
Are nano-particles safe for marine life?
Research shows that zinc oxide nano-particles caused coral bleaching under controlled conditions (Adler and DeLeo 2020). However, available data may not adequately account for realistic reef conditions and UV filter concentrations.
How Sunscreen Impacts the Ocean
In areas where there are lots of swimmers and snorkelers, sunscreen washes off people's bodies and can reach such high concentrations that the sunscreen chemicals are toxic to marine life. Honestly though, sunscreen is just a tiny drop in the sea when it comes to threats to the ocean. Climate change is the predominant driver of coral reef bleaching.
Plastic production has a huge carbon footprint and is a significant source of ocean pollution. Here's why our sunscreen is plastic-free:
Instead of using plastic, we package our sunscreen in aluminium tins that are infinitely recyclable. Aluminium is so recyclable that nearly 75 percent of all the aluminium ever produced is still in use today. You can keep your tin in circulation by wiping out your empty tin and popping into your recycling bin.
Are chemical sunscreens or mineral sunscreens better?
There are many advantages of using a zinc sunscreen. Here are 3 of the main reasons we recommend using a mineral sunscreen instead of chemical -
Gentle on the skin: Zinc oxide is considered to be non-irritating and suitable for all skin types, including sensitive skin. Unlike some chemical sunscreens, zinc oxide is less likely to cause skin irritation, making it an ideal choice for individuals with delicate or reactive skin.
Immediate protection: Zinc sunscreens start working as soon as they are applied to the skin. There's no need to wait for any chemical reactions to take place, unlike some chemical sunscreens that require approximately 20 minutes to become effective.
Stability: Zinc sunscreens maintains their effectiveness over time, providing reliable protection throughout sun exposure. Chemical sunscreens tend to degrade which is one of the reasons many sunscreen brands fail to meet their SPF claims.
Finally, A Zinc Sunscreen That Goes on Clear
Adler, B.L. and DeLeo, V.A., 2020. Sunscreen Safety: a Review of Recent Studies on Humans and the Environment. Curr Derm Rep 9, 1–9.
Cole, C., Shyr, T., & Ou‐Yang, H., 2016. Metal oxide sunscreens protect skin by absorption, not by reflection or scattering. Photodermatology, photoimmunology & photomedicine, 32(1):5-10.
Mohammed, Y. H., Holmes, A., Haridass, I. N., Sanchez, W. Y., Studier, H., Grice, J. E., H., Benson & Roberts, M. S., 2019. Support for the safe use of zinc oxide nanoparticle sunscreens: lack of skin penetration or cellular toxicity after repeated application in volunteers. Journal of Investigative Dermatology, 139(2):308-315.