Advantages or disadvantages of using zinc oxide in sunscreen?

Leading into the advantages and disadvantages of using zinc oxide in sunscreen, zinc oxide as a common ingredient in the pharmaceutical field and cosmetics fields will be introduced in detail. Therefore, we could have a general impression of what zinc oxide is before getting into this product that is so common, sunscreen, which is applied every single day on our skin to ward off the harm from the sun. We will have a basic concept of different types of sunscreens, how effective are they, what it does to human skin, and the side effects of it with different ingredients.

Basic information on zinc oxide

The chemical compound zinc oxide’s formula is ZnO, and it is an inorganic compound with 2 formula units. The natural appearance of pure ZnO at room temperature is in white powder, therefore it is called zinc white, Chinese white, calamine, and other names. However, ZnO found in nature is from a kind of rare mineral called zincite, which occurs to be yellow to red due to the manganese inside, apart from the fact that most of the ZnO used in production these days is synthetic. It has no odor whatsoever and with a density of 5.6 g/cm³. The chemical structure of it is wurtzite, while the coordination geometry of it is tetrahedral. It melts at a very high temperature, 1,974 °C (3,585 °F; 2,247 K), while boils at an even way higher temperature, 2,360 °C (4,280 °F; 2,630). It has a very low thermal conductivity, which would be 0.6 W/(cm·K).

Basic features of zinc oxide

From the above-listed chemical properties, there are some special features of zinc oxide, let’s have a look in order to understand how and on what it is applied, and the advantages and disadvantages of using zinc oxide in sunscreen. There are so many applications for zinc oxide, it is one of the additives in a lot of daily commodities including cosmetics. Most of the applications of zinc oxide deploy the reactivity that the oxide exchange between other zinc-related chemical compounds.

From its basic chemical compound features, zinc oxide is highly refractive, in other words, it could ward off UV lights. Besides, it is highly thermally conductive, besides, it has the properties of capabilities to bind, and it is antibacterial as well. It is hardly soluble in water but could dissolve meeting most of the acids, for instance, hydrochloric acid.

Application of zinc oxide

With all those special features, zinc oxide is applied in multiple industries of producing daily commodities, for example, rubber production, ceramic production, food production, pigment coatings, and of course, cosmetics, and sunscreens. Then it might come back to the question, what are the advantages and disadvantages of using zinc oxide in sunscreen?

However, the most common use of zinc oxide is for pharmaceutical use. It is a very common ingredient in a lot of medicine.

First of all, dentistry. Calamine lotion, a mixture of zinc oxide and iron oxide, is very commonly used, it could restore and as dental prosthetics. Meanwhile, a lot of mouthwash and toothpaste are added with zinc oxide to prevent bacteria and to alleviate bad breath, as well as to prevent plaque and tartar.

Being antibacterial, zinc oxide is added to medical products like zinc oxide tape, cotton, rubbers, etc.

Furthermore, one of the most common uses of zinc oxide in the medical field is external ointments, creams, and lotions. Zinc oxide is often added to those and various dermatological products to treat skin problems. Atopic dermatitis is one of the most common conditions, and there are eczema, rash, and acne. Therefore, zinc oxide can be found in various cosmetic products apart from prescription drugs.

And here we’re back to the main topic, the advantages or disadvantages of using zinc oxide in sunscreen. With its feature of being highly refractive, zinc oxide is added into most of the sunscreen products in creams, and ointments and now sprays as the main ingredient to block UVA and UVB, which is the most common physical sunscreen. It is not irritating, not easy to cause allergy, and not comedogenic with its features.

However, there might be some small disadvantages to using zinc oxide in sunscreen. Zinc oxide might be absorbed by the skin by a tiny amount. And the particles might be a pollution source to the ocean as well.

Conclusion:

Zinc oxide is a very commonly used chemical compound in various fields including a pharmacist, rubber production, food, ceramics, and outer materials like paint, pigments, etc. with its features of being highly refractive, it is mostly added in sunscreen products with some disadvantages of using zinc oxide in sunscreen.