Our customers often ask us how much zinc oxide should a sunscreen have? The answer is fairly complex, but it breaks down into 4 basic parts:
- Why use zinc oxide sunscreens?
- The importance of non-nano zinc oxide
- FDA's limit on zinc oxide
- What percentage should you look for?
Why use zinc oxide sunscreens?
Zinc oxide (ZnO) is a compound of zinc and oxygen and, unlike common sunscreen ingredients, is biochemically matched to human systems. It is the only sunscreen active ingredient FDA-approved for use on children less than 6 months old. Zinc is a critical mineral element used to keep humans healthy and found in many multivitamins.
Zinc oxide works by forming a barrier that protects skin from UV rays as well as moisture and irritants. Zinc oxide holds tight to its electrons when it absorbs UV energy, limiting creation of free radicals that cause oxidative damage or increase the risk of skin cancer. Most importantly for UV defense, and unlike ANY other active sunscreen ingredient (including titanium dioxide), it covers the ENTIRE UVA-UVB-UVC spectrum, and vitally at the same effectiveness. In other words, it protects deep tissues just as well as surface tissues.
This isn't true of any other ingredient, or collection of ingredients.
The importance of non-nano zinc oxide
Non-Nano Zinc Oxide is the best sunscreen active ingredient, for both human and marine biosystems. If a product uses non-nano, it will state this clearly within the ingredients; otherwise, it is almost assuredly NANO (meaning particle sizes less than a nanometer) and should not be used, because zinc oxide is toxic to most marine biosystems, including coral reefs. (Such products are usually marketed as “sheer” and “clear.”)
Remember, the term "reef safe" is not regulated, and any product can claim it, regardless of its ingredients.
Non-nano zinc oxide is highly stable under most conditions, including when hit with UV rays. It absorbs UV energy via band gap absorption (it reflects and scatters visible light, that’s why it looks white), preventing skin penetration and cell damage.
FDA's limit on zinc oxide
Topical zinc oxide products have been available in the US before 1938. As an active ingredient in over-the-counter sunscreen and skin protectant products, the FDA allows for a concentration of zinc oxide up to 25%. In 2019, the FDA proposed that zinc oxide be classified as safe and effective, in contrast to petrochemicals, none of which the FDA recognizes as safe.
In addition to sunscreen, zinc oxide is used in food fortification. Zinc oxide is often added to cereals and nutrition bars to increase the nutritional value. Inorganic compounds such as zinc oxide can be safely used under FDA regulations.
Waxhead sunscreens use ONLY top-quality food-grade non-nano zinc oxide.
What percentage zinc to look for?
We recommend looking on the sunscreen label for a zinc oxide concentration of 20-25% for best protection from UVA and UVB rays. In general, the more zinc oxide, the higher the UV protection, regardless of various products' stated SPF values (many of which are achieved by gaming the SPF tests by using anti-inflammatory ingredients to suppress the skin's natural red reaction).
It is so important to read sunscreen labels and understand the ingredients used in your skincare products. And remember, many companies label their products as “reef-safe” simply because they don’t contain a few of the currently banned petrochemical ingredients, but they contain several other petrochemical ingredients that make them completely UNSAFE for reefs and other marine life, not to mention their long term toxicity to humans.
Always read the ingredients, know what those ingredients do, and decide for yourself.
Did you know?
All Waxhead Sunscreens have 25% non-nano Zinc Oxide. A recent customer said, “Waxhead is the only one that can hold up under hot and humid conditions.” Try some for yourself. Click the button below to learn more.