Chemical vs. Physical Sunscreens – What’s the Difference?
by Staff Writer
Sunscreen is a must when you'll be outdoors. Your skin requires protection from ultraviolet (UV) energy to remain free of sunburn and to decrease your chance of skin cancer, and the right sunscreen used correctly can provide that protection. There are many sun protection options on the market with something for every need, but if you're like many people, you may be unsure exactly which type is best for you. One of the most important things to understand about sunscreen is the difference between chemical and physical formulas, as picking the ideal type will help to ensure that the sunscreen you use is friendly to your skin, fully protective from UV and suitable for your preferences.
How UV Rays Affect the Skin
Before you can fully understand how chemical and physical sunscreens differ, it's important to know just how ultraviolet rays affect the skin. Sunlight is made up of many kinds of light, and UV is just one type in its spectrum. UV is invisible and can't be detected, but it is always present in sunlight, even on cloudy days. Ultraviolet is broken into different types based on the length of its waves. The longer waves are called ultraviolet A (UVA), and they have the ability to penetrate the skin, making them responsible for damage that causes wrinkles and contributes to skin cancer. Ultraviolet B (UVB) rays are shorter and cannot travel past the outer layer of your skin. These rays are what cause sunburn, and they also play a role in skin cancer formation.
Physical sunscreens are natural minerals that do not dissolve. They remain on the surface of the skin and create a shield between your skin and the sun. When ultraviolet light strikes this shield, it is reflected away before it can reach the skin. Titanium dioxide and zinc oxide are the two physical sunscreen ingredients approved by the FDA for use in sunscreen products. Zinc oxide provides complete protection against UVA and UVB, while titanium dioxide guards against UVB and some types of UVA.
Chemical Absorbers of UV
Chemical absorbers of ultraviolet are synthetic ingredients that are absorbed by the skin. Each type is capable of absorbing certain types of ultraviolet, preventing it from acting on the skin cells. The FDA has approved 15 ingredients for use as chemical absorbers in sunscreen. None of these ingredients can offer complete protection against the sun, so manufacturers typically combine multiple chemical absorbers to fully meet the sun protection needs of the skin.
Choosing a Formula
So how do you decide which type of sunscreen to purchase? When you choose a physical sunscreen, you can be certain that you're receiving protection from UVB and at least some UVA rays. With a chemical formula, you'll need to confirm that a product is labeled as a "broad-spectrum" sunscreen to be assured of complete UVA and UVB protection. If you have sensitive skin, choosing a physical sunscreen will pose less of a risk of irritation. However, some people find physical sunscreens to be more difficult to apply or less comfortable to wear, as they tend to be thicker, heavier formulas.
No matter which type of sun protection product you use, you need to apply it correctly to get best results. Always use at least 1 ounce and cover all exposed areas from head to toe, reapplying at least every 2 hours to keep yourself protected.