Zinc Oxide Sunscreen: How Does It Work?

Modern sunscreen is something of a miracle product when you think about it. It can protect you from the radiation of the sun – the most powerful energy source in our solar system – and stop your skin from getting terribly burned even if we spend all day basking in the sun’s rays. No one likes having to deal with soreness and peeling skin because they didn’t apply enough sunscreen during a day spent at the beach!

Many of the most powerful sunscreen products rely on zinc oxide: a kind of mineral that is especially good at reflecting the harmful radiation that would otherwise burn our skin. Today, we’ll break down zinc oxide sunscreen and go over how it works, as well as why you should prioritize it when shopping for a bottle of new sunscreen.

Zinc Oxide – How Does It Work for Sunscreen?

Zinc oxide is a powdered mineral derived from, you guessed it, zinc. When in its powdered form, the zinc oxide mineral bits can reflect sunlight, preventing it from penetrating your skin and causing damage. In fact, earlier sunscreens were much more powdery than the creamy, soothing stuff we enjoy today.

Because it is a powder, sunscreen products do not use zinc oxide by itself. It would be difficult to keep zinc oxide dust on your skin--sunscreens rely on other ingredients to act as a carrier, creating a creamy or smooth texture, and making the zinc oxide stick to your skin. In this way, the zinc oxide powder bits get into your pores faster and are easy to wash out at the end of the day.

Green Goo’s Solar Goo Sunblock is a perfect example of these principles in action--zinc oxide is combined with skin-protecting calendula oil and five other simple, nourishing, all-natural ingredients. A single application can protect your skin for up to 40 minutes, and the sunscreen is water-resistant and broad-spectrum with an SPF rating of 30.

Zinc Oxide Benefits

There are lots of reasons why sunscreen manufacturers using zinc oxide as their active ingredient:

  • Zinc oxide is almost invisible to the naked eye, and manufacturers can grind it down into a powder that is barely noticeable even in direct sunshine
  • Furthermore, zinc oxide has protective properties. This makes it’s additionally helpful if you need to rub sunscreen onto an area of skin with small micro-incisions or tears, like skin on your leg that has tiny cuts from rolling in the sand outside.
  • Zinc oxide is non-comedogenic, meaning it won’t clog your pores to cause acne or excessively oily skin.
  • Beyond all these other benefits, zinc oxide is one of the most efficient minerals at reflecting UVA and UVB rays.

Is Zinc Oxide a Natural Ingredient?

Yes. Although zinc oxide has the type of name you would expect from a chemical or synthetic element, it’s completely natural and has been used by humans for hundreds of generations: way before the first chemical labs were ever even conceived of.

So, it’s totally possible to find natural zinc oxide sunscreen products. You can also find zinc oxide in additional natural protective products, like lip balm. Green Goo makes a great plant-based lip balm that contains zinc oxide, beeswax, orange, and vanilla, and other botanical ingredients that protect your lips from daily wear and tear, dehydration, and sun damage all at the same time.

What About Titanium Dioxide?

The other common active ingredient in sunscreen products is titanium dioxide. This natural and powdered mineral is derived from titanium, and it’s often used in sunscreen and other cosmetics for its lubricating and thickening properties.

  • Titanium dioxide is also relatively invisible to the skin, as well as non-comedogenic and gentle.
  • However, titanium dioxide doesn’t provide as much protection from UVA radiation. This makes zinc oxide a better all-around sunscreen ingredient for those concerned with getting the best sun protection possible.

Are There Any Side Effects of Using Zinc Oxide Sunscreens or Lip Balms?

While zinc oxide will be effective for most people, there is always the risk of a few side effects.

You might experience a mild allergic reaction. For this reason, it’s a good idea to try a little bit of any new sunscreen product before rubbing it all over your body. This way, you can stop using the sunscreen if a small patch of skin showcases an allergic reaction.

Most commonly, people might find that using zinc oxide sunscreen causes their skin to appear somewhat pasty or to obtain a translucent sheen. If this bothers you, you can make a point to look for sunscreens that rub in clear, though this is minor compared to the skin damage you protect yourself from when using sunscreen!

How Do Sunburns Occur, Anyway?

There are two types of radiation you need to know about: ultraviolet A and B, also known as UVA and UVB.

Both types are ultraviolet rays emitted by the sun. There’s technically a third type of UV radiation called UVC, though these rays are typically stopped by the Earth’s atmosphere before reaching your skin. Because of this, sunblock focuses on protecting you from UVA and UVB radiation exclusively.

Your skin becomes sunburned when your skin comes into contact with UVA and UVB radiation for too long. Both types of rays have different effects:

  • UVA radiation can penetrate deep into the skin and reach all the way to the dermis, which is the thickest layer of your skin. It’s also the radiation responsible for making your skin age faster and develop wrinkles.
  • UVB rays are shorter in length and can burn the surface of your skin. These rays cause most of the superficial sunburn damage we are used to, although they can also cause skin cancer over time if you repeatedly get badly sunburnt.

Modern sunblock (called “broad-spectrum”) generally protects your skin from both types of radiation with the help of active ingredients like zinc oxide.

How Does Sunscreen Help?

Chemical and physical sunscreen both help protect your skin from UVA and UVB radiation in different ways.

Chemical sunscreen operates very differently from physical sunscreen – the ingredients used in these products can react to sunlight and transform the radiation into heat, which eventually evaporates away from your skin. Physical sunscreen, which is the kind that uses zinc oxide, involves using natural compounds that physically block solar radiation from reaching your skin.

Some ingredients are better at absorbing sunlight, while others can reflect UV radiation and prevent it from penetrating your skin entirely.

There are several advantages to using a physical sunscreen over a chemical sunblock.

Physical sunscreen:

  • Will begin protecting your skin as soon as it is applied. Chemical sunscreen usually takes around 20 minutes to begin working.
  • Lasts longer when exposed to UV radiation.
  • Is gentler on the skin and is less likely to clog up your pores, so it’s also good for sensitive skin!

The SPF Scale

On a regular bottle of broad-spectrum sunscreen, you’ll notice a rating called the SPF rating. SPF stands for “Sun Protection Factor”, and it’s a single number that represents how well a given sunscreen product can protect your skin from UVB rays. Unfortunately, there isn’t a scale that can measure how well sunblock protects you from UVA radiation. Still, any broad-spectrum sunscreen can protect your skin from both types of rays.

Higher SPF values are almost always better to a point. Most dermatologists will recommend that people use sunscreen products with SPF ratings between 15 and 50. However, SPF 15 already provides protection from about 94% of UVB rays, and SPF 45 already provides 98% UVB protection, so paying extra to get SPF higher than that won’t actually provide you with much more benefit--no matter how high you go, you’ll never have 100% protection. So, all in all, about SPF 30 gives you the best bang for your buck!

How to Use Sunscreen Properly

Although plenty of people use zinc oxide sunscreen, not everyone is sure they’re using it correctly.

  • Make sure to start with clean, dry skin in order to make sure the sunscreen can adhere and absorb properly.
  • Be sure to use enough sunscreen – don't be stingy with the stuff! Feel free to apply a decent layer over any skin that will be exposed to the sun for more than a half-hour.
  • Even water-resistant sunscreen can wash off, especially if the protected skin in question comes into frequent contact with other surfaces or skin. This is most common with the hands and arms.
  • Always reapply sunscreen when the product recommends. For Green Goo’s Solar Goo Sunblock, you should reapply the sunscreen about every 40 minutes to every hour.


At its core, zinc oxide is a critical component for some of the most effective natural sunscreen products you can find. Anyone looking to spend some time in the sun should make sure they have a great sunscreen made with natural ingredients like zinc oxide!





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