Sun-Sational Choices: Your Ultimate Guide to Picking the Perfect Sunscreen!

drjlarsen7
Jun 23
4 min read

Have you ever stood perusing the sunscreen aisle and felt COMPLETELY OVERWHELMED by the myriad of choices?

How do you know which one to choose?

Well, I’ve got answers to your questions (including the ones you didn’t know you should be asking)!

Question: What is “SPF” and why is it important?

SPF stands for Sun Protection Factor. It measures how well a sunscreen protects your skin.
You want to choose a broad-spectrum sunscreen with a minimum SPF of 30.
- Broad-spectrum means that the sunscreen shields against both UVB (which leads to sunburn) and UVA (which contributes to wrinkles and age spots).

Question: Do I really need to reapply sunscreen every few hours? Or are they just trying to sell me more sunscreen?

There is no such thing as completely waterproof or sweatproof sunscreen. Even those that claim to be waterproof or water resistant need to be reapplied frequently.
In addition, sunscreen ingredients can break down over time when exposed to sunlight, reducing their effectiveness.
You should reapply sunscreen every two hours, or more frequently if you're swimming, sweating, or toweling off often.

Question: I’ve heard a lot of hype about mineral sunscreens, but are they really better? What is the difference between mineral sunscreens and chemical sunscreens?

Mineral-based sunscreens are the safest options: The FDA recognizes only two compounds as generally safe and effective sunscreens: zinc oxide and titanium dioxide. These ingredients work by "blocking" ultraviolet radiation. Zinc oxide protects against both UVB and UVA rays, while titanium dioxide primarily offers UVB protection with less effectiveness against UVA.
Be mindful that the active components in mineral sunscreens tend to separate more easily compared to those in chemical sunscreens. Therefore, it's essential to shake mineral sunscreens in liquid form prior to application.
Chemical sunscreen agents may provide better protection than mineral sunscreens if you’re in the water for extended periods. However, they are not widely recognized as safe and effective. These agents work by "absorbing" radiation, but they penetrate the skin and enter the body. The FDA has requested more safety data from manufacturers on these compounds, including octocrylene, as well as avobenzone, ensulizole, homosalate, octinoxate, octisalate, and oxybenzone.
Avoid sunscreens that combine mineral-based ingredients (like zinc oxide or titanium dioxide) with chemical sunscreen ingredients, especially those containing avobenzone. This mixture may diminish the effectiveness of certain chemical compounds and could potentially generate toxic compounds when exposed to sunlight.
Some chemical sunscreens have been found to contain carcinogenic compounds, including benzene and benzophenone, likely stemming from other ingredients such as butane, isobutane, or propane, which are used as propellants in aerosol sprays.

Question: How well does clothing work as a sunscreen? Do certain colors or types of fabrics protect better than others?

While any clothing can offer some protection against UV radiation, certain fabrics outperform others. Dark or bright fabrics (e.g., red, black, or navy) and less porous materials (e.g., polyester, cotton blends, or fabrics used in p
olo shirts) generally provide better UV protection than light-colored fabrics (e.g., pastels, yellow, or white) and porous materials (e.g., linen or knitted fabrics).

Question: It seems a shame to throw away expired sunscreen, especially when it can be so expensive. Is it a problem to use expired sunscreen?

Research from the U.S. and France indicates that benzophenone, a harmful compound, can form through the degradation of octocrylene, a common (chemical) sunscreen ingredient.
In 2019, nearly 3,000 U.S. sun products included octocrylene. This compound is a mutagen, a carcinogen, and an endocrine disruptor (meaning it can mimic or interfere with our hormonal balance). It is banned in food products in the U.S. and noted under California Proposition 65 as UNSAFE in personal care items.
Tests reveal that benzophenone levels in sunscreen with octocrylene increased steadily over time and more than doubled when the products are stored at elevated temperatures. One significant study showed that products containing octocrylene had benzophenone levels about 100 times higher than those sunscreens labeled "octocrylene-free." Additionally, expired products contained double the benzophenone, highlighting ongoing production of benzophenone over time as the sunscreen degraded.
For these reasons, I recommend avoiding any sunscreen which contains octocrylene or oxybenzone, ESPECIALLY IF THEY ARE EXPIRED. (Li, Environ Sci Technol 2022)