Sunscreen vs. Sunblock
The words sunscreen and sunblock are often used interchangeably, but sunblock is actually an outdated term that the Food and Drug Administration has banned from use. The correct way to distinguish between these two are ‘chemical sunscreen,’ for what you may think of as plain old sunscreen, and ‘mineral sunscreen,’ for what is no longer referred to as sunblock.
Here are important things to know about how sunblock and sunscreen compare:
- How It Works: Chemical sunscreens absorb the sun’s rays and prevent most of them from penetrating the skin.
- What’s In It: Chemical sunscreens typically use a combination of UVA- and UVB-absorbing chemicals and create a thin film on the skin to minimize UV penetration.
- When It Works: Chemical sunscreens takes about 15 minutes after application to be effective, so you need to plan ahead. And some chemical ingredients break down in the sun, so you have to be diligent and reapply regularly – about every two hours, and after each time you go in the water or towel off.
- How It Feels: Compared to mineral sunscreens, chemical sunscreens come in a greater number of formula options including sprays, and they usually rub in easily and are invisible on the skin.
- Why Use It: For the hopefully obvious reasons of helping to prevent sun burn, skin damage and reducing the risk of skin cancer.
- How It Works: Mineral sunscreen sits on top of the skin, absorbing, reflecting and scattering the sun’s rays.
- What’s In It: Mineral sunscreens are traditionally sourced from natural minerals titanium oxide and zinc oxide, in very fine powder form dispersed into sunscreen formations, including liquids, sprays and solids.
- When It Works: After 20 minutes, same as chemical sunscreen.
- How It Feels: Mineral sunscreens can sometimes be thick and opaque, harder to spread and more noticeable, leaving a white film. Some people find them messy and difficult to wash off.
- Why Use It: Same as chemical sunscreen – to protect your skin and reduce the chances of contracting skin cancer. The American Academy of Dermatology says that products with zinc oxide or titanium dioxide may be less irritating and thus a good choice for those with sensitive skin, babies and toddlers.
In a Nutshell:
Using a broad-spectrum version of either mineral or chemical sunscreen, rated to at least 30 SPF, will block 97 percent of the sun’s rays. The choices come down to personal preference.
Ultimately, the differences don’t matter too much as long as you are using one or the other. These days, you may not even need to make a choice because many products combine some of each.
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This article includes information from the U.S. Food and Drug Administration.
©Johnson & Johnson Consumer Inc. 2019