Physical vs. Chemical Sunscreen, What's the Difference?
Sunscreen: We know we have to wear it, but whoever said choosing one is easy was wrong. There are a handful of factors at play—from varying SPF levels to finding the best formula for your skin type—but did you also know there are two general types of sunscreen to consider?
When it comes to physical vs. chemical sunscreen, what’s the difference? Which one is right for you? We reached out to board-certified dermatologist, and Skincare.com consultant, Dr. Elizabeth B. Houshmand, for answers to the physical vs. chemical sunscreen debate!
WHAT IS PHYSICAL (MINERAL) SUNSCREEN?
Physical sunscreen—or mineral sunscreen—contains active mineral ingredients zinc oxide and/or titanium dioxide, two ingredients that offer broad-spectrum coverage against both UVA and UVB rays. “Physical block is made of zinc and/or titanium oxide and it acts like a wall that does not absorb in the skin,” says Dr. Houshmand. “It sits on the skin as a protective layer.”
Often referred to as physical blockers, these ingredients sit on top of the skin to deflect and scatter damaging UV rays away from the skin. One of our favorites is SkinCeuticals Physical Fusion UV Defense SPF 50.
Dr. Houshmand is a big fan of physical sunscreens for their quick-action and non-irritable formulas. “These mineral-based formulas provide instant protection upon application,” she says. “Mineral formulas tend to be less likely to irritate the skin.” She recommends physical sunscreen for those with heat-activated skin concerns, such as rosacea or redness, since the formula can deflect the heat and energy given off by the sun away from the skin. Dr. Houshmand also noted that most physical sunscreens offer protection against both UVA and UVB rays and are naturally broad spectrum.
Need some more reasons to opt for a physical sunscreen? Dr. Houshmand said that they’re less likely to clog pores, therefore making them a great choice for acne-prone skin types.
WHAT IS CHEMICAL SUNSCREEN?
Chemical sunscreen contains organic (carbon-based) active ingredients which absorb UV light. “Chemical sunscreen is made up of chemicals such as octylcrylene, avobenzone, octinoxate, octisalate, oxybenzone, homosalate and helioplex,” Dr. Houshmand says. “It acts like a sponge, and absorbs or scatters the UV rays your skin is exposed to.”
Chemical filters offer coverage against UVA and UVB rays, but the range of protection depends on the combination of active ingredients used. One of our favorites is La Roche-Posay Anthelios 60.
Dr. Houshmand said that one of the biggest benefits of chemical sunscreens is that they’re available in multiple formulations, like aerosol sprays, lotions, and sticks, making them easier to apply.
However, this type of sunscreen does have a few downsides. According to Dr. Houshmand, chemical sunscreens can cause irritation for sensitive skin types. “Additionally, the sun can break down their effectiveness over time, so it’s important to reapply throughout the day,” she says.
PHYSICAL VS. CHEMICAL SUNSCREEN
Physical sunscreens should work as soon as you apply them, whereas chemical sunscreens typically require about 20 minutes to reach full effectiveness, according to Dr. Houshmand. The texture of physical sunscreen is typically denser, thicker and more opaque than chemical sunscreens, and can often appear chalky and ashy against darker skin tones. In addition, physical sunscreens tend to rub off more easily with sweat and water than chemical formulas, meaning more frequent reapplication when outdoors may be necessary. However, the sun can naturally break down the barrier of chemical sunscreens, which also means you’ll have to reapply them throughout the day, even if you’re doing minimal activity outside.
In terms of which is right for you, the answer is not so matter-of-fact since all formulas are not created equal. You’ll find that some formulas will contain both chemical and physical blockers, which can help narrow down your pick. More important than the type of sunscreen you use (except for using one that is broad-spectrum, that’s a biggie) is making certain that you wear it—all day every day. Promise?
Editor’s note: There’s currently no sunscreen on the market that blocks out 100 percent of UV rays. For that reason, it’s important to pair your sunscreen use with additional sun protection measures such as seeking shade, wearing protective clothing, and avoiding peak sun hours when rays are strongest.