Your Ultimate Guide To Decoding Sunscreen Ingredient Labels

Sunscreen is one step in the strategy that we can use to protect against skin cancer and premature skin aging. While it is not a cure-all against the effects of sun radiation, it does go a long way towards preventing the sun's rays from damaging skin in a few different ways. However, certain individuals are more predisposed to sun issues.

As the Skin Cancer Foundation explains, your genetics, overall health, and any skin conditions you may have can put some people at more risk than others. While everyone, regardless of their background, should consider applying sunscreen, it's also essential to know how this product actually works to ensure you get the best protection from sun damage.

By learning about the ingredients in sunscreen, you can better understand what it is actually protecting you against and whether the ingredients themselves pose any risk. For instance, as we will discuss, there are specific chemicals in sunscreens that may not be as safe as first thought. The FDA highlights that some of the active components in sunscreen can stay in the bloodstream long after use. Though it says this may not necessarily be a bad thing (in that it is harmful), more research is needed to examine its use in the long term.

According to the FDA, some of the most common active ingredients used as sun filters are avobenzone, octisalate, octocrylene, homosalate, oxybenzone, octinoxate, titanium dioxide, and zinc oxide (descending by popularity). However, of these, only two are viewed as both generally safe and effective in recent research by the FDA — namely, zinc oxide and titanium oxide, which incidentally fall at the end of their list.

The FDA's research considered a number of factors that contribute to the safety of active sunscreen products, including both clinical and toxicological data on a wide spectrum of active ingredients, looking at how well they protect against sun damage, their duration, and any applicable side effects, such as irritation. The FDA suggests that only two currently met an acceptable standard based on these criteria, and because of these findings, it has since proposed amending all sunscreen ingredients, requiring them to meet a new standard of performance.

You can find the reasoning behind implementing these new stringent rules in various research. For instance, in the Journal of Photodermatology, Photoimmunology & Photomedicine, researchers note organic compounds like oxybenzone and many of the others at the top of the FDA list get absorbed into the skin, which can go on to cause hormonal disruptions as they enter the bloodstream. Their concentration in sunscreen formulas will likely be reduced under the new FDA proposal since they far exceed what the current research recommends.

The other ingredients you need to be aware of are usually moisturizers, fragrances, and emollients, which give the product an overall pleasant feel on the skin, making it feel hydrated. These ingredients can vary from product to product based on the brand and how they market their product. For instance, the Journal of Applied Pharmaceutical Sciences and Research explains that close to 3,000 chemical fragrances control the scent of sunscreens and other cosmetics. Even those who list fragrance-free formulas actually add fragrances that mask the smell of the product.

Moisturizers and emollients are usually easier to identify. These might include water-attracting agents called humectants, such as glycerine, or those that prevent water loss, like petroleum-based ingredients, paraffins, silicones (you can often spot these by the "cone" suffix added at the end of the ingredient), or mineral oils. Emollients have a slightly different function than these moisturizers.

According to the New Zealand Trust dermatological resource DermNet, emollients are used to "soften and smooth skin." They work by covering the skin with a protective film which can soothe irritation and act as a barrier to lock in moisture. You might see these listed as some form of lanolin obtained from sheep's wool, bee wax, a stearic acid derivative, or plant sterols (a protein found in plant cell walls).

There are three types of sun radiation: UVA, UVB, and UVC (per the FDA). UV is short for ultraviolet radiation. It is just under the range of visible light on the light spectrum, measured by wavelengths. Each category of UV, from A to C, goes in descending order from the longest wavelength (UVA) to the shortest (UVC).

Because of UVA rays' length, these typically have the most impact on the skin. As Montrose Dermatology and Cosmetics explains, UVA has the most penetrative power, reaching several layers down into the skin, followed by UVB, which can go down two layers, and UVC, which just about passes through the first layer. As you might have guessed, this is why UVC isn't often mentioned in suncare protection, as it isn't as damaging as its counterparts.

Active sunscreen ingredients have different capabilities in reducing or preventing the damage of UVA and UVB, with the majority focusing on UVA, which is the most damaging. However, as mentioned, broad-spectrum formulas can also protect against UVB. That said, it is still recommended that you should apply at least 2 mg. of sunscreen per centimeter squared of skin, as research by the Journal of Clinical and Aesthetic Dermatology points out that people often use just a quarter of this amount.

First, physical and mineral are not two distinct types of sunscreen; they are the same thing. Physical sunscreens contain active mineral (i.e., inorganic) ingredients such as titanium dioxide and zinc oxide, which act as a "physical" barrier to reflect UV light from the skin's surface. They do not absorb into the skin, instead leaving a chalky, white appearance. As such, physical sunscreens offer the most protection. "With physical blockers, if you can still see it, it's still working," dermatologist Anisha Patel, M.D., tells The University of Texas Cancer Center.

Chemical sunscreens, on the other hand, contain organic ingredients that absorb UV radiation, convert it into heat, and then release it from the skin. Some active ingredients in chemical sunscreens include oxybenzone, avobenzone, and octinoxate. They are available in cream and spray form, and their application is more comfortable than physical sunscreens. But since chemical sunscreen works through absorption, there has been some concern, as demonstrated in the Journal of Cutaneous Medicine and Surgery, as it may adversely affect your health and the environment.

For instance, student research at Rappahannock Community College highlights that in a study of over 650 sunscreen products, nearly two-thirds were either harmful or ineffective — particularly in the case of oxybenzone, which can accumulate in blood and water and even cause damage to DNA. Thus, there has been a push to move to mineral sunscreens to avoid these issues.

"Dermatologist tested" and "dermatologically tested" labels are commonly found on sunscreens and cosmetics products as a way for brands to demonstrate that their products are trustworthy. But as dermatologist Dr. Dray explains, when a sunscreen product claims to be dermatologically tested, it simply means that a dermatologist or a doctor somewhere has used the product. However, it does not necessarily mean that the dermatologist or doctor approves of the product or that it is the consensus of dermatologists everywhere that people should use it.

In fact, the claim "dermatologically tested" may have been obtained through a consumer survey that gathered feedback on what products dermatologists would or would not recommend. That isn't to say that a product that doesn't make this claim isn't safe or approved. The FDA ensures sunscreen manufacturers are legally responsible for ensuring that their products are safe when used according to the directions on the labeling, as well as in the way that you'd traditionally expect to use the product. 

Although the FDA doesn't require specific tests on sunscreens or any cosmetic products, manufacturers can use safety data already available on individual ingredients and products with similar formulations. While this might suggest to some that no testing is occurring, the key point is that manufacturers still have the legal responsibility to ensure the safety of their products, including sunscreens. They also have to use safety data or perform additional tests to make claims regarding a product's efficacy.