What Is Zinc Oxide? How much Should Be In Sunscreen?


As usual, people wear sunscreens when they want to spend time outdoors. The purpose of the lotion is to protect the skin from the direct impact of sunlight and add a beautiful glow to it. However, the ability of sunscreens to do these things is only due to the active ingredients in them. These ingredients vary from one brand to another.

Because different ingredients exist, it may be almost impossible to know what to choose to use. One thing, however, is certain: whatever works for the skin and remains eco-friendly is always a good deal. That is why people are advised to go for biodegradable sunscreens over non-biodegradable ones because they provide good benefits to the skin and still considers the environment.

Zinc Oxide is one of the few active ingredients you will find in sunscreens, but not many people know that. In this article, you will discover what the mineral is and how much percentage is perfect for the ideal sunscreen.

What is Zinc Oxide?

One of the best natural minerals for skincare products is Zinc Oxide – an oxidized Zinc. It is an effective ingredient because it blocks different UV rays that may adversely affect the skin. Some of these harmful rays include UVA, UVB, and UVC.

How Does Zinc Oxide Work in Sunscreens?

As described above, Zinc Oxide is an active blocker of harmful UV rays that may damage the skin. However, the efficacy of this mineral doesn’t just come to be without some reactions taking place to ensure that the skin is protected. Using biodegradable sunscreen (with this ingredient) ensures a protective barrier between the skin and the sun.

On application of zinc oxide sunscreens, generally, white residues are deposited on the skin, meaning the ingredients aren’t absorbed into the skin; instead, it settles on the skin. It contains insoluble filters that are not absorbed into the body. When washing up, the lotion ends up in the oceans, which may or may not affect the health of marine creatures.

For biodegradable sunscreen, the effect of the skincare product may not affect marine health; however, for non-biodegradable sunscreen, it is toxic to marine life. The reason is that the former contains non-particles greater than 30nm, in which anything less than 35nm is always toxic to marine life (i.e., the former).

How Much Should Be in Sunscreen?

One of the many trending debates in the world today regarding skincare products is: what percentage of zinc oxide is enough. Regardless of how natural a mineral Zinc Oxide is, it should still be delivered in the right quantities. Many consumers worry that getting a sunscreen, for example, with too much of this ingredient, may negatively affect their skin.

However, dermatologists have lent their opinion as regards this sensitive issue. They claim that biodegradable sunscreens are somewhat great because there is no threat to both the user and the life existing wherever it eventually ends up (i.e., the world oceans).

Ideally, these biodegradable lotions contain two active minerals as physical sunblocks – Zinc Oxide and Titanium Dioxide. The concentration of these minerals in the right quantities makes them effective for use without causing damaging effects on the skin.

According to dermatologists, the two acceptable concentrations that will deliver great effects on the skin are:

Only Zinc Oxide at conc. above 15% – SPF 24. The ideal choice for dark-skinned people.

Zinc Oxide at conc. between 15 and 20% + 5% Titanium – SPF 32 to SPF 37

However, Zinc Oxide at conc. above 25% is dangerous.

How Dangerous is Zinc Oxide? Does it Cause Cancer?

Since many skincare products are significant triggers and causes of skin cancer today, people have reservations for sunscreens and whatever else they apply to the skin. However, most people don’t realize that sunscreens protect humans against the damaging effects of UV rays, instead of destroying them. The after-effect on where it ends, i.e., oceans, is the only thing that makes them dangerous.

Biodegradable sunscreens containing Zinc Oxide are not harmful to humans, but there could be cases of allergies, depending on the person involved. They are also not dangerous to marine life because they have particles greater than 30nm, making them difficult to consume or impossible to kill marine organisms.

Overall, Zinc Oxide provides great health benefits than people realize. It is an active ingredient in treating infections, acne, rash, skin irritation, and repairing damaged tissues.

How to Use Zinc Oxide? – The Do’s and Don’ts

As much as the natural mineral offers great benefits to the skin, there are do’s and don’ts to ensure its active performance.


Sunscreens with Zinc Oxide ingredients must be thoroughly checked if it is water-resistant or not. If the formulation is, it would be best to re-apply every 30 to 60 minutes for fresh effects and performance on the skin.

Always try to use clear zinc oxide formulations, and add makeup primers for lasting effects.

Using the right amount of zinc oxide sunscreen on the skin is beneficial to health – about a shot glass (i.e., 1 oz.)


Until you are outside, do not try to apply the zinc oxide sunscreen. Zinc oxide works quickly, and you don’t want it that way if indoors.

The skin needs total protection against damaging UV rays; hence, you shouldn’t forget to apply everywhere. Even though the hands, neck, and chest are the hotspots, you shouldn’t hesitate to apply them to other exposed areas.

Lastly, do not buy a sunscreen that dermatologists cannot vouch for its efficacy.

Read more on how to use reef-safe sunscreens when scuba diving.


As much as people are interested in taking care of their skin, it is important to be informed on the ingredients of the products they use. The essence of having this piece of information is so that they can know whether the skincare product really helps them or not. From this article, it is quite obvious that Zinc Oxide, in the best concentration, does a great deal of good to the skin, blocking harmful UV rays and ensuring a good glow.